Number, Ranking and Time Sequence Test Questions and Answers

Answer: A

The fourth ranker is Charan.

Kiran is 2nd and Tarun 3rd. The first ranker is the shortest and is not Charan; Sravan is taller than one person, so he is not the shortest either. The first ranker is therefore Pavan, the shortest, and Sravan is the second shortest.

Charan and Sravan take ranks 4 and 5. The fourth ranker is the tallest, and Sravan is second shortest, so Charan is 4th and tallest, and Sravan 5th. Tarun is taller than Kiran, which fixes the middle heights.

Pavan is the first ranker, Tarun is stated to be third, and Sravan, as the second shortest, cannot be the tallest person who holds fourth rank.

Answer: D

Four persons are taller than Pavan.

Kiran is 2nd and Tarun 3rd. The first ranker is the shortest and is not Charan; Sravan is taller than one person, so he is not the shortest either. The first ranker is therefore Pavan, the shortest, and Sravan is the second shortest.

Charan and Sravan take ranks 4 and 5. The fourth ranker is the tallest, and Sravan is second shortest, so Charan is 4th and tallest, and Sravan 5th. Tarun is taller than Kiran, which fixes the middle heights.

Pavan is the first ranker, and the first ranker is the shortest of the five, so all the other four (Sravan, Kiran, Tarun and Charan) are taller than him. One, Two and Three would leave someone shorter than Pavan, which the clues rule out.

Answer: C

The number is 132.

Rearrange each number's digits in descending order:

324 → 432, 456 → 654, 572 → 752, 683 → 863, 726 → 762, 132 → 321.

The smallest result, 321, comes from 132. 683, 572 and 456 become 863, 752 and 654, all larger.

Answer: C

There are two even numbers.

Swap the first and third digits of each number:

324 → 423, 456 → 654, 572 → 275, 683 → 386, 726 → 627, 132 → 231.

A number is even when its last digit is even; after the swap, the last digit is the old first digit. Only 654 and 386 end in an even digit, so the count is two.

Answer: D

There are 6 such odd numbers.

Treating each digit as a number, the perfect squares among single digits are 1, 4 and 9 (1 counts, since \(1 = 1^{2}\)). Reading the sequence 4 3 1 5 7 8 3 1 6 2 9 7 1 2 1 3 5 2 6 8 6 5 4 3 2 1 3 8 7, the odd digits that come straight after one of them are:

4-3, 1-5, 9-7, 1-3, 4-3 and 1-3, at positions 2, 4, 12, 16, 24 and 27.

That makes 6. Leaving out 1 as a perfect square would give only 3 (the pairs after 4 and 9), which is why the smaller options appear.

Answer: D

The number is 5.

The tenth digit from the left is the one in position 10, and seventh to its right is position \(10 + 7 = 17\). Counting along 4 3 1 5 7 8 3 1 6 2 9 7 1 2 1 3 5 ..., position 10 is 2 and position 17 is 5.

Counting seven places from position 10 and landing on position 16 instead (an off-by-one slip) would give 3, one of the distractors.

Answer: C

There is 1 such odd number.

Among single digits, the perfect cubes are 1 and 8, and the perfect squares are 1, 4 and 9. An odd digit is needed with a cube just before it and a square just after it.

The only place this happens is 8 3 1 at positions 6, 7 and 8: 3 is odd, 8 before it is a cube (\(2^{3}\)), and 1 after it is a square. Every other odd digit fails on one side, for example the 3 at position 16 has 1 before it but 5 after it.

Answer: C

There are 47 girls in the row.

Mamta is 17th from the left and fourth to the right of Rita, so Rita is \(17 - 4 = 13\)th from the left. Parvati is 12 places to the right of Rita, so she is \(13 + 12 = 25\)th from the left.

Parvati is also 23rd from the right, so the total is:

\[ 25 + 23 - 1 = 47 \]

One is subtracted because Parvati is counted in both positions. The other totals come from miscounting one of the positions or forgetting to subtract the shared place.

Answer: C

His rank from the top stays 14th. Rank from the top counts only the students placed above him. New students are added at the bottom of the list, below him, so none of them goes above Sanjiv and the number of students ahead of him is unchanged at 13. The class size rises from 37 to 46, which changes his rank from the bottom (it was \(37 - 14 + 1 = 24\) and becomes 33), but not his rank from the top. The answers 12th, 13th and 15th would need a student to leave from, or join, the part of the list above him, and the question says nothing of the kind.

Answer: A

Fourteen more singers are needed. A singer who is 19th from the top and 38th from the bottom stands in a group of \(19 + 38 - 1 = 56\) singers, because that singer is counted in both ranks. To make the group 70 the number to add is \[ 70 - 56 = 14 \] so 14 more are needed. The options 16 and 18 overshoot the gap, and 10 leaves the group at 66. If the question were read as asking for the group itself, the answer would be 56, which is not offered, so the question is read as the number to be added, which the key confirms.