3b · Test 3 · Depth Perception Test · RRB ALP CBAT
Hidden Cube Test छिपे घन परीक्षण
Kind 3b of Test 3, the Depth Perception Test of the RRB ALP CBAT, is the Hidden Cube Test. The hall gives 50 questions in 10 minutes, one pile of blocks a question. You count the blocks that the others hide on every side: no face, edge or corner in view. What it checks is whether you can place the blocks a drawing proves but never shows, at 12 seconds a pile. In the last exam (CEN 01/2024) the hall gave this kind for Test 3, as the institute's records show.
The screen shows the piles in parts, each pile with its number options on one line. All blocks in a pile share one size and shape. One click on the pile's line records your count; Save & Next brings the next part while Time Left runs. Below are the screen flow, the RDSO guideline's three-block rule and a shortlist method. The worked example, the slips that cost marks and a 7-day plan follow. After that, a practice paper gives you the hall's 50 piles and 10-minute clock.
RRB ALP CBAT के तीसरे टेस्ट, गहराई बोध परीक्षण, में परीक्षा हॉल दो में से एक प्रकार देता है; छिपे घन परीक्षण (3b) उनमें से एक है। इसमें 10 मिनट में 50 सवाल होते हैं और हर सवाल में गुटकों का एक ढेर दिखता है। गिनना उन गुटकों को है जिनकी कोई सतह, कोई किनारा या कोई कोना नहीं दिखता, यानी जो चित्र में हैं तो ज़रूर, पर नज़र नहीं आते।
The hall's own count and clock, as the RDSO guideline (ALPs Guidelines CBT, Jan 2020) gives them. Each pile has a row of numbers on one line; click the number equal to your count.
Sit a free Full Mock with the Depth Perception Test, on a screen like the hall
All five tests in one sitting, the hall's order and timing, a scorecard out of 30 and your T-Score in each test. Free with every account, no package needed.
पाँचों टेस्ट एक बार में, असली क्रम और समय, हर टेस्ट का T-Score। हर अकाउंट के साथ मुफ़्त।
How the test runs on screenस्क्रीन पर कैसे चलता है
- 1
Instruction screen
An instruction screen in Hindi and English opens the test with three practice piles, solved as 2, 4 and 3. The portal allows this screen 5 minutes; Skip Instruction takes you straight in.
- 2
Several piles to a screen
The piles arrive in parts. Each pile on the screen has its own line of numbers, and the question numbers run on to 50.
- 3
One click records the count
A click on a number saves that pile's answer. When every pile in the part has one, Save & Next brings the next part, until pile 50 is done.
- 4
One clock for 50 piles
The whole test runs on a single Time Left clock of 10 minutes. Fifty piles in 10 minutes is 12 seconds a pile; one look at the clock after each part is enough.
- 5
Submit and review
The test ends at Submit or when Time Left reaches zero. Your T-Score comes with a review that puts the correct count under every pile. In a Full Mock, Test 4 follows a short break with a summary.
A worked exampleउदाहरण
- In Practice Problem I of the RDSO guideline, two blocks are completely hidden: no side or corner of either shows.
- Practice Problems II and III follow on the same instruction screen.
The RDSO guideline's answers are 2, 4 and 3.
The method: how to attempt a questionतरीका
- 1
Set the back row first
The RDSO guideline's rule: the base of the farthest row always has three blocks. Place that row in your mind before anything else. It fixes how deep the pile goes and how much can stand behind what you see.
- 2
Build the pile layer by layer
Start at the bottom layer and work up. Every block above the base needs a block beneath it, so the drawing proves blocks it does not show. Fix each layer in your mind, hidden blocks included; you test them in the next two steps.
- 3
Shortlist the inside
A block is hidden only when covered on three sides: on top, in front and on the side you look at. So the front row, the highest layer and the end of every row on the side you see are out. Only the inside blocks remain.
- 4
Test the shortlist
Ask of each block: does any part of it reach your eye? A sliver of an edge or the tip of a corner puts it out. Count the blocks where the answer is no, click that number, move on.
6 tips that raise the scoreसुझाव
1.Do not total the pile
The answer is the hidden count alone. Counting every block and then subtracting the visible ones doubles the work and the slips. Go straight to the blocks the pile encloses and test only those.
2.Count the back row before the front
The farthest row has three blocks at its base, even when the blocks in front hide them all. Any of those three with a block in front, above and on its open side is hidden. Forget the row and you miss them.
3.Twelve seconds, then the next pile
Twelve seconds is one pile. A pile that passes it gets your closest count and a move on; the clock does not wait for a recount. An answer always beats a blank.
4.Keep this test apart from the Brick Test
You prepare both kinds of Test 3. The Brick Test asks how many bricks touch a lettered brick; this one asks how many blocks are completely covered. Fix the rule on the instruction screen and keep to it for all 50 piles.
5.Land every click on its own line
Several piles share one screen, so pile 7's count can land on pile 8's line. Put the pointer on the line, glance at its pile once more, then click. This is mouse work; sit the papers on a laptop or desktop, not a phone.
6.Practise on a laptop or desktop
The portal works on a phone too, but the exam hall is a desktop screen with a mouse. Sit every practice paper and Full Mock on a laptop or desktop, so the screen, the mouse and the pace are the ones you will meet on the day.
Mistakes that cost marksगलतियाँ
- Counting a block as hidden when its top edge or one corner still shows.
- Leaving out the three base blocks of the farthest row because the rows in front hide them.
- Using the Brick Test's touching rule here and counting neighbours instead of covered blocks.
- Clicking the number on another pile's line, since several piles share a screen.
- Chasing one doubtful block through three rebuilds of the pile while the final part of the paper goes unanswered.
A 7-day plan for the Hidden Cube Test7 दिन की योजना
| Day | What to do |
|---|---|
| Day 1 | Work the three practice piles with pencil and paper: draw each layer from the bottom and mark the covered blocks. Check your counts against 2, 4 and 3. |
| Day 2 | One paper at your own speed. On every pile, place the back row's three base blocks first, then stack forwards and upwards. |
| Day 3 | Review day, no new paper. For each wrong pile of Day 2, name what fooled you: a top face, a front face or a corner tip. |
| Day 4 | Shortlist drill: strike out the front row, the top layer and open ends in one look, then test only the inside. One paper at your normal speed. |
| Day 5 | Clock day. Hold 12 seconds a pile; when a pile passes it, click your closest count and go on. Every line filled matters more than a perfect first part. |
| Day 6 | Second attempt on the Day 2 paper, then one new paper. A paper keeps the highest of up to 3 attempts, so the retry is worth sitting with care. |
| Day 7 | Free Full Mock on a laptop or desktop, in the order of the railway's mock. Notice how Depth Perception feels as the second test, straight after the Memory Test, and where its T-Score stands against 42 and the target of 60. |
Questions students askसवाल-जवाब
▸How long is the Hidden Cube Test, and how many piles come in it?
50 questions in 10 minutes, one pile a question, on one Time Left clock. That is 12 seconds a pile, or 5 piles a minute.
▸Hidden cube test kaise hota hai? What does one question look like on screen?
Each question shows a pile of blocks of one size and shape. You count the blocks the others hide on every side, no face, edge or corner showing, and click that number.
▸Which blocks count as hidden in the Hidden Cube Test?
Hidden means nothing of the block can be seen. A block on top, a block in front and a block on its open side cover it fully. The RDSO guideline's first practice pile has two such blocks.
▸Can a block in the bottom layer be hidden?
Yes. A base block is hidden when a block sits on it, one stands in front and one closes its open side. The farthest row's three base blocks are often hidden this way.
▸Will the hall give the Hidden Cube Test or the Brick Test for Test 3?
One of the two; you do not know in advance. In the last exam (CEN 01/2024) the hall gave the Hidden Cube Test, as the institute's records show. Prepare both. For CEN 01/2025 the railway's mock link gives the Brick Test (3a) instead, so give the Brick Test the first papers and keep this one ready.
▸Is there negative marking in the RRB ALP psycho test?
No. The CBAT has no negative marking. Attempt every question; an unanswered question is a mark lost for certain.
▸What T-Score do I need to pass?
A T-Score of at least 42 in each of the five tests of the CBAT. The portal shows your T-Score on every paper the moment you submit, measured against everyone who sat it.
▸Can I practise on my phone?
Yes, the portal runs on a phone. But the CBAT is taken on a desktop with a mouse, so Kautilya Classes advises every student to sit the practice papers and Full Mocks on a laptop or desktop: the same screen, the same mouse, the same pace as the hall.
▸How do I practise this test on the portal?
Every account gets one free Full Mock after login: all five tests in one sitting with the hall's timing and a scorecard with your T-Score in each test. Practice papers of every kind, with the hall's count and clock, come with a Kautilya Classes package. New students message the team on WhatsApp; Kautilya Classes students get their login from the institute.
सारांश (हिंदी में)
RRB ALP CBAT के तीसरे टेस्ट, गहराई बोध परीक्षण, का प्रकार 3b छिपे घन परीक्षण है: 10 मिनट, 50 सवाल, हर सवाल के लिए 12 सेकंड। हर सवाल में गुटकों का ढेर है और वही गुटके गिनने हैं जिनकी कोई सतह, किनारा या कोना नहीं दिखता; एक कोना भी दिखे तो वह गुटका छिपा नहीं है। सबसे पीछे की पंक्ति के आधार में हमेशा तीन गुटके होते हैं; वहाँ से ढेर को परत दर परत बनाइए और केवल अंदर के गुटकों की जाँच कीजिए। पिछली परीक्षा (CEN 01/2024) में परीक्षा हॉल ने तीसरे टेस्ट में यही प्रकार दिया था, ऐसा संस्थान के रिकॉर्ड बताते हैं। पोर्टल के प्रैक्टिस पेपर में परीक्षा हॉल की तरह 50 ढेर और 10 मिनट की घड़ी मिलती है, और जमा करते ही T-Score के साथ हर ढेर का सही उत्तर दिखता है; लॉगिन के बाद पहला फुल मॉक मुफ़्त है।
The other kinds of Depth Perception Test
The hall gives one of them for Test 3; practise them all.
- 3a · Brick Test
ईंट परीक्षण
50 questions · 5 min
The other four tests of the CBAT
- Test 1 · Memory Test
स्मृति परीक्षण
6 kinds of question
- Test 2 · Following Directions Test
निर्देश पालन परीक्षण
3 kinds of question
- Test 4 · Power of Observation Test
अवलोकन शक्ति परीक्षण
4 kinds of question
- Test 5 · Perceptual Speed Test
प्रत्यक्ष गति परीक्षण
5 kinds of question
New to the exam? Start with the complete guide to the RRB ALP psycho test, or see all 20 kinds of question on one page.