IBM Permutation And Combination Quiz -1

Let the four digit number be ′aaab′ or ‘baaa′.

Since, the number has to be a multiple of 9, therefore
3a+b should be either 9, 18 or 27.

Case I: 3a+b=9
Possible cases are: (1116,6111,2223,3222,3330,9000)

Case II: 3a+b=18
Possible cases are: (3339,9333,4446,6444,5553,3555,6660)

Case III: 3a+b=27
Possible cases are: (6669,9666,8883,3888,7776,6777,9990)

Hence, total number of cases is 20.

possibility of knowing c++= 4/10
possibility of knowing java=2/4

there are 4 possibilities,
a person knows java but not c++=2/4*(1-(4/10))=3/10
a person knows c++ but not java= 4/10*(1-(2/4))=1/5
possibility of knowing neither =2/8
therefore, probability of knowing any one language only= 3/10+1/5=1/2
therefore ,possibility of knowing both= total probability-
probability of knowing neither- probability of knowing
anyone language only
total probability is always 1
so, required probability= 1 -(2/8) -(1/2) =1/4

Condition 1: 1/each boy says he has equal brothers and sisters.
So if he has 3 sisters and 3 brothers excluding him then
in total there are 4 boys and 3 girls.

Condition 2: If a/each girl says she has twice no of brothers than sisters, so going with option A satisfies this as well because excluding that girl (the one being considered) she has 2 more sisters and 4 brothers.
So the answer is:
4 Boys and 3 Girls.

Currently there is no PrepInsta Explanation. Did you know?

You can also submit your own version of explanations under user explanation section and also view other submitted explanations by other users.

6 digit number where first 2 digit are fixed .
1*1*8*7*6*5 =1680

5 subjects can be arranged in 6 periods in 6P5 ways.
Remaining 1 period can be arranged in 5P1 ways.

Two subjects are alike in each of the arrangement.
So we need to divide by 2! to avoid overcounting.

Total number of arrangements = (6P5 x 5P1)/2! = 1800

Alternatively this can be derived using the following approach.
5 subjects can be selected in 5C5 ways.
.Remaining 1 subject can be selected in 5C1 ways.

These 6 subjects can be arranged themselves in 6! ways.
Since two subjects are same, we need to divide by 2!
Total number of arrangements = (5C5 × 5C1 × 6!)/2! = 1800

we can go in any bus out of the 25 buses.
Hence
He can go in 25 ways.

Since we can not come back in the same bus that
he used for travelling,
we can return in 24 ways.

Total number of ways = 25 x 24 = 600

Let batch of cheques on monday = X
On tuesday processed three times= 3X
On wednesday processed= 4000
Total cheques processed in 3 days =16000
X+3X+4000=16000
.\'. X=3000
Cheque processed on Tuesday 3X= 3*3000=9000
.\'. Ans is 9000

Currently there is no PrepInsta Explanation. Did you know?

You can also submit your own version of explanations under user explanation section and also view other submitted explanations by other users.

Right Side =15 seat
Left Side =15-3 (3 few seat in right side)= 12 seat
Total= 15+12= 27
People can seat in 27 seat= 27*3=81
People can seat in Last Seat = 7
Total People can seat= 81+7=88