# Bank PO Questions

Q:

A number of cats got together and decided to kill between them 999919 rats. Every cat killed an equal number of rats. Each cat killed more rats than there were cats. How many rats do you think that each cat killed ?

 A) 1009 B) 991 C) 2000 D) 1000

Explanation:

Given total number of rats = 999919

999919 = 1000000 - 81 = $\inline \fn_jvn \small 1000^{2}-9^{2}$ = (1000+9)(1000-9) = 1009 x 991.
Since there were more rats than there were cats, 991 cats killed 1009 rats each.

Filed Under: Math Puzzles
Exam Prep: AIEEE , Bank Exams , CAT , GATE
Job Role: Bank Clerk , Bank PO

1 3
Q:

fifteen persons are sitting around a circular table facing the centre. What is the probability that three particular persons sit together ?

 A) 3/91 B) 2/73 C) 1/91 D) 3/73

Explanation:

In a circle of n different persons, the total number of arrangements possible = (n - 1)!
Total number of arrangements = n(S) = (15 – 1)! = 14 !
Taking three persons as a unit, total persons = 13 (in 4 units)
Therefore no. of ways for these 13 persons to around the circular table = (13 - 1)! = 12!
In any given unit, 3 particular person can sit in 3!. Hence total number of ways that any three person can sit =
n(E) = 12! X 3!
Therefore P (E) = probability of three persons sitting together = n(E) / n(S) = 12! X 3 ! / 14!
= 12!x3x2 / 14x13x12! = 6/14x13 = 3/91

1 1
Q:

A box contains 90 screws each of 100 gms and 100 bolts each of 150 gms. If the entire box weighs 35.5 kg, then the weight of the empty box is ?

 A) 10.5 kgs B) 12 kgs C) 9.6 kgs D) 11.5 kgs

Explanation:

Screws weight = 90x100 = 9000gms
bolts weight = 100 x 150 = 15000gms
weight = screws + bolts => 24000 gms =>24 kg
Given entire box weight = 35.5kg
empty box = entire box weight - weight => 35.5kg - 24kg => 11.5kg
so the empty box is 11.5kg.

1 0
Q:

640 ml of a mixture contains milk and water in ratio 6:2. How much of the water is to be added to get a new mixture containing half milk and half water ?

 A) 360 ml B) 320 ml C) 310 ml D) 330 ml

Explanation:

Here total parts of milk and water in the solution is 6+2 = 8 parts
1part = 640/8 = 80
old mixture contains 6parts of milk and 2 parts of water(6:2).
To get new mixture containing half milk and half water, add 4parts of water to the old mixture then 6:(2+4) to make the ratio same.
i.e, 4 x 80 = 320 ml.

1 0
Q:

At 6′o clock a clock ticks 6 times. The time between first and last ticks is 30 seconds. How long does it tick at 12′o clock ?

 A) 66 sec B) 55 sec C) 36 sec D) 24 sec