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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

Answer:   C) 28

Explanation:

$\therefore$ 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:  $\inline \overset{3}{\leftarrow}C\overset{8}{\leftrightarrow}B\overset{5}{\leftrightarrow}A\overset{21}{\rightarrow}$

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

Case II: $\inline \overset{3}{\leftarrow}C\; \; A\overset{5}{\leftrightarrow}B$

Number of persons between A and C

= (8 - 6) = 2                                   $\inline [\because C\overset{8}{\leftrightarrow}B, A\overset{21}{\rightarrow}]$

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.

Q:

Manoj and Satya are ranked seventh and eleventh respectively from the top in a class of 31 students. What will be their respective ranks from the bottom in the class ?

 A) 25th and 21st B) 26th and 22nd C) 20th and 24th D) 24th and 20th

Answer & Explanation Answer: A) 25th and 21st

Explanation:

Number of students behind Manoj in rank = (31 - 7) = 24.

So, Manoj is 25th from the bottom.

Number of students behind Satya in rank = (31 - 11) = 20.

So, Satya is 21st from the bottom.

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2 296
Q:

If the positions of the first and the third digit within each number are interchanged, which of the following will be the third digit of the second lowest number ?

987, 514, 658, 487, 404, 269

 A) 8 B) 9 C) 2 D) 4

Answer & Explanation Answer: D) 4

Explanation:

According to the question, after the position of the first and third digit interchanged new numbers are
789, 415, 856, 784, 404, 962

962, 856, 789, 784, 404, 415
Here the second lowest number is 404 and the last digit of it is '4'.

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4 404
Q:

Some boys are sitting in a row. P is sitting fourteenth from the left and Q is seventh from the right. If there are four boys between P and Q, how many boys are there in the row ?

 A) 26 B) 24 C) 25 D) 22

Answer & Explanation Answer: C) 25

Explanation:

Number of boys in the row = number of boys uptil P + number of boys between P and Q + number of boys including Q and those behind Q = 14 + 4 + 7 = 25.

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3 311
Q:

In a queue, Amrita is 10th from the front while Mukul is 25th from behind and Mamta is just in the middle of the two. If there be 50 persons in the queue. What position does Mamta occupy from the front ?

 A) 14th B) 16th C) 18th D) 20th

Answer & Explanation Answer: C) 18th

Explanation:

Number of persons between Amrita and Mukul = 50 - (10 + 25) = 15. Since Mamta lies in middle of these 15 persons, so Mamta`s position is 8th from Amrita i.e. 18th from the front.

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5 344
Q:

In a row, Kumar is at 7th place from the left and Pawan is at 9th place from the right. When they interchange the positions Kumar becomes 11th from left. How many were seated in the row ?

 A) 19 B) 20 C) 21 D) 27

Answer & Explanation Answer: A) 19

Explanation:

Initialy from left 7th = kumar
from right 9th = pawan
Interchange kumar = 11th from left, from right kumar = 9th;
11+8 = 19;
8 is 1,2,3,4,5,6,7(pawan),8,9,10,11(kumar),12,13,14,15,16,17,18,19;
simply count the 9th place from right we will get total as 19.

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1 359