In how many ways 5 balls can be placed in 3 boxes, if any box can have any number of balls
- 15
- 125
- 243
- 32
Anwer (3) 243 ways Solution Each ball has 3 different options hence total ways = 3*3*3*3*3 = 243 ways
Question of the day
What is the maxium score of a batsman in a 10 over cricket, if there are no no balls and no batsman can run more than 4 runs between the wickets.
- 180
- 315
- 310
- 333
Answer: (4) Solution: Batsman can make 33 runs in an over and can still retain strike. (by taking triple on the last ball) hence total 330 runs in 10 overs, but he can hit a six instead of taking a triple on the last ball, so total 333 runs.
A sum of money becomes 4 times under compound interest in every 6 years. In how many years the money will become 32 times of itself
- 48 years
- 18 years
- 15 years
- 24 years
Anwer: (3) 15 years Solution: px^6 = 4p (where x= (1+r) x^3 = 2 now it will be become 32, when power is raised to 5 on both sides x^15 = 32 hence after 15 years money will become 32 times of itself
A man, woman and a boy can complete a work in 5, 10 and 20 days respectively. How many boys must assist 2 man and 4 woman to compete the work in 2 days.
- 2 boys
- 4 boys
- 8 boys
- can’t be determined
Answer: (2) 4 boys Soltution (work) w = 5m days = 10w days= 20b days…….(1) now (2m + 4w+ xb)1day = w……..(2) now from (1) equation m = 4b w= 2b put the values in (2) equation (8b+8b+xb) days = work = 20 b days from this x = 4
There are 5 green, 5 blue and 5 red balls are there in a bag. What is the minimum number of picks to ensure that there are 2 balls of same colors are picked
- 11
- 6
- 4
- 2
Anwer: (3) 4 picks Solution worst case scenario is first 3 picked balls are of different color. The moment 4th ball is picked it will be one of the three colors only. Hence minimum 4 picks to ensure that 2 balls are of same color
Total number of integers pairs (x,y) that satisfy the equation
4x+3y = 3xy
- 2
- 3
- 1
- infinite many
Anwer: (2) 3 pairs Solution 3xy-4x = 3y x= 3y/(3y-4) x= 1+ 4/(3y-4) now x will be integer when 3y-4 is a factor of 4 (both positive and negative values) hence 3y-4 = 1 , 2 , 4 , -1, -2 , -4 y will be 5/3, 2, 8/3, 1, 2/3, 0 hence y will be integer on 3 of those values. Hence there are 3 integer pairs of (x,y) that satisfy the above equation.
If a couple has 4 children then what are the chances that 2 of them are girls and 2 of them are boys.
- 1/2
- 3/8
- 1/16
- none of these
Answer: (2) 3/8 Solution: Total ways: 2*2*2*2 = 16 possibilities Favorable ways: There are 4C2 = 6 ways to select the 2 places out of 4. Let’s call those 2 places boys so other 2 places will become girls. hence probability = 6/16 = 3/8
For how many integers
- 1
- 2
- 0
- infinite many
Anwer: (1) 2 Solution: factorize the expression (m-3)(m-4) for the above expression to be prime one of the factors should be 1 or -1 when m-3 = 1 or -1 , then m = 4 or 2 4 doesn’t give prime, 2 will make the value of expression = 2, which is prime when m-4 = 1 or -1 , then m= 5 or 3, 5 will make expression = 2 Hence for values =2 and 5, this expression will be prime.
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