Quantitative Aptitude - Arithmetic Ability Questions

Given speed of the person = 8 1/2 = 17/2 kmph
Let the speed of the stream = x kmph
speed of upstream = 17/2 - x
speed of downstream = 17/2 + x
But given that,
2(17/2 - x) = 17/2 + x
=> 3x = 17/2
=> x = 2.83 kmph.

The total number of ways of forming the group of ten representatives is ²²C₁₀.
The total number of ways of forming the group that consists of no seniors is ¹⁰C₁₀ = 1 way
The required number of ways = ²²C₁₀ - 1

since it is a combination = 38C17 = 2878 x 10^10

(100-x)%  of 88% of 8400 = 6896

=> 100-x10088100x8400 = 6896

=> x = 6.709%

let the diagonals of the squares be 2x and 5x respectively

ratio of their areas = 12*2x2 :12*5x2= 4:25

18 Feb, 2016 = (2015 years + Period from 1.1.2016 to 18.2.2016)

Odd days in 1600 years = 0

Odd days in 400 years = 0

15 years = (12 ordinary years + 3 leap year) = (12 x 1 + 3 x 2)= 4 odd days

Jan  Feb

(31 + 18 ) = 49 days

49 days = (7 weeks + 0 day)= 0 odd day.

Total number of odd days = (0 + 0 + 4 + 0) = 4 odd day.

Given day is Thursday

Let the interest rate be r%

We know that,

S.I = PTR/100

=> (1540 x 5 x r)/100  +  (1800 x 4 x r)/100 = 1788

=> r = 178800/14900 = 12%