Quantitative Aptitude - Arithmetic Ability Questions

Probability of not hitting the ball = 1- 1/4 =
Then, the probability that the batsman will hit the ball =

t=I/pr

Given Lasya can do a work in 16 days.

Time taken by Rashmi = n days

=> (12 x 20)/(20 - 12) = (12 x 20)/n

=> n= 30 days.

Required ratio of efficiencies of Rashmi and Lasya = 1/30  ::  1/16  = 8 : 15.

Number of books that can be placed in the larger box is given by Volume of Box / Volume of book.
Now, n = 25 x 42 x 60 / 7 x 6 x 5
= 63000 / 210
= 300.
Therefore, 300 books can be in that box.

We know that, Total probability = 1

Given probability of black stones = 1/4

=> Probability of blue and white stones = 1 - 1/4 = 3/4

But, given blue + white stones =  9 + 6 = 15

Hence,

3/4 ----- 15

 1   -----  ?

=> 15 x 4/3 = 20.

Hence, total number of stones in the box = 20.

We are not given a value of P in this problem, so either pick a value

for P and stick with that throughout the problem, or just let P = P.

We have that t = 1, and r = .055. To find the effective rate of interest,

first find out how much money we have after one year:

A = Pert

A = Pe(.055)(1)

A = 1.056541P.

Therefore, after 1 year, whatever the principal was, we now have 1.056541P.

Next, find out how much interest was earned, I, by subtracting the initial amount of money from the final amount:

I = A − P

  = 1.056541P − P

  = .056541P.

Finally, to find the effective rate of interest, use the simple interest formula, I = Prt. So,

I = Pr(1) = .056541P

.056541 = r.

Therefore, the effective rate of interest is 5.65%

Present age of Sony = 24 + 4 = 28 years

After 5 years Renuka's age = 7×5 + 5 = 40 years

Let the distance travelled by Tilak in first case or second case = d kms

Now, from the given data,

d/20 = d/22 + 36 min

=> d/20 = d/22 + 3/5 hrs

=> d = 132 km.

Hence, the total distance travelled by him = d + d = 132 + 132 = 264 kms.