Number, Ranking and Time Sequence Test Questions

Q:

How many such pairs of digits are there in the number 421579368 each of which has as many digits between them in the number as when they are arranged in ascending order?

 A) None B) One C) Two D) Three

Explanation:

Given Number:     4  2  1  5  7  9  3  6  8

Ascending order:  1  2  3  4  5  6  7  8  9

Hence the required pairs are  12, 49, 16

491 37213
Q:

How many 4's are there preceded by 7 but not followed by 3?

5  9  3  2  1  7  4  2  6  9  7  4  6  1  3  2  8  7  4  1  3  8  3  2  5  6  7  4  3  9  5  8  2  0  1  8  7  4  6  3

 A) Four B) Three C) Six D) Five

Explanation:

7  4  2

7  4  6

7  4  1

7  4  6

Only at these placees 4 is preceded by 7 but not followed by 3

222 30211
Q:

In a row of boys, If A who is 10th from the left and B who is 9th from the right interchange their positions, A becomes 15th from the left. How many boys are there in the row ?

 A) 23 B) 31 C) 27 D) 28

Explanation:

Clearly, A’s new position is 15th from the left. But this is the same as B’s earlier position which is 9th from the right.

318 19178
Q:

Sam ranked 9th from the top and 38th from the bottom in a class. How many students are there in the class ?

 A) 45 B) 47 C) 46 D) 48

Explanation:

Number of students in class = (8 + 1 + 37) = 46

79 12737
Q:

Nitin ranks 18th in a class of 49 students. What is rank from the last ?

 A) 31 B) 18 C) 32 D) 19

Explanation:

Number students behind the nitin in rank = (49 - 18) = 31

Nitin is 32nd from the last

142 9165
Q:

How many such digits are there in the number 7346285 which are as far away from the beginning of the number, as they will be when arranged in ascending order within the number?

 A) None B) one C) Two D) Three

Explanation:

Given Number : 7346285

Ascending Number : 2345678

Answer is Two. Those digits are 3,4

43 7260
Q:

Three persons A, B and C are standing in a queue. There are five persons between A and B and eight persons between B and C. If there be three persons ahead of C and 21 persons behind A, what could be the minimum number of persons in the queue?

 A) 41 B) 40 C) 28 D) 27

Explanation:

Three persons A, B, C can be arranged in a queue in six different ways, ie ABC, CBA, BAC, CAB, BCA, ACB. But since there are only 3 persons ahead of C, so C should be in front of the queue. Thus, there are only two possible arrangements, ie CBA and CAB.

We may consider the two cases as under:

Case I:  $\stackrel{3}{←}C\stackrel{8}{↔}B\stackrel{5}{↔}A\stackrel{21}{\to }$

Clearly, number of persons in the queue = (3+1+8+1+5+1+21=) 40

Case II:

Number of persons between A and C

= (8 - 6) = 2

Clearly number of persons in the queue = (3+1+2+1+21) = 28

Now, 28 < 40. So, 28 is the minimum number of persons in the queue.

65 7246
Q:

A class of boys stands in a single line, One boy is 19th in order from both the ends, How many boys are there in the class ?

 A) 37 B) 39 C) 27 D) 38

Explanation:

Number of boys in the class = (18 + 1 +18) = 37