Quantitative Aptitude - Arithmetic Ability Questions

Here, S = {1, 2, 3, 4, ...., 19, 20}.

Let E = event of getting a multiple of 3 or 5 = {3, 6 , 9, 12, 15, 18, 5, 10, 20}.

P(E) = n(E)/n(S) = 9/20.

Let the number be x.

Then, ideally he should have multiplied by  x by 5/3. Hence Correct result was x * (5/3)= 5x/3. 

By mistake he multiplied x by 3/5 . Hence the result with error  = 3x/5 

Then, error = (5x/3 - 3x/5) = 16x/15 

Error %  = (error/True vaue) * 100 = [(16/15) * x/(5/3) * x] * 100 = 64 %

52.5% of 800 + 30.5% of 2800 = ? + 87.30

420 + 854 - 87.30 = ?

1274 - 87.30 = ?

? = 1186.70

There are two series (8, 11, 14, 17, 20) and (7, 12, 17, 22) increasing by 3 and 5 respectively.

 Total sale for 5 months = Rs. (6435 + 6927 + 6855 + 7230 + 6562) = Rs. 34009.

 Required sale = Rs.[(6500 x 6) - 34009]

= Rs. (39000 - 34009) 

= Rs.  4991.

In each number except 383, the product of first and third digits is the middle one.

In given Series, all the numbers except 54 are multiples of 5.

3 pairs of gloves = 2 x 54 = 108 ; 1 pairs of gloves = 36
3 pairs of leg pads = 2 x 36 = 1 pairs of leg pads = 24
3 cricket balls = 2 x 24 = 48
cost of 1 cricket ball = 16;