Quantitative Aptitude - Arithmetic Ability Questions

A=R[(1+i)^n-1]/i(1+i)^n

Let present age of Pranay = 15p

That of Sai = 17p

ATQ,

15p + 6/17p + 6 = 9/10

=> 150p + 60 = 153p + 54

=> p = 2

Therefore, Age of Pranay after 6 yrs = 15 x 2 + 6 = 36 years.

Any number which can be expressed as a fraction of two integers like P & Q as P/Q where Q is not equal to zero.

Every integer is a rational number since Q can be 1.

Hence, in the given options, 4 can be expressed as a simple fraction as 4/1. And all other options cannot be expressed as fractions.

Hence, 4 is a rational number in the given options.

Two digit numbers: The two digits can be 2 and 9: Two possibilities 29 and 92.

Three-digit numbers: The three digits can be 1, 2 and 9 => 3! Or 6 possibilities.

We cannot have three digits as (3, 3, 2) as the digits have to be distinct.

We cannot have numbers with 4 digits or more without repeating the digits.

So, there are totally 8 numbers.

a/(a + b) = 15/21 → a = 15, a + b = 21

→ b = 21– 15 = 6
⇒ a – b =15 – 6 = 9
⇒ (a + b)/(a – b) = 21/9

m=j/i