Quantitative Aptitude - Arithmetic Ability Questions

Given the ages of Sunitha and Pranitha are 40 years and 60 years.

Let before 'm' years, their ages be in the ratio of 3 : 5

ATQ,

40-m60-m = 35

=> 200 - 5m = 180 - 3m

=>2m = 20

=> m = 10 years.

P.W. = Rs. (1600 - 160) = Rs. 1440
∴ S.I. on Rs.1440 at 5% is Rs. 160.
∴ Time = [100 * 160 / 1440 * 5] = 20/9 years = [20/9 * 12] months = 27 months.

Given that x = 2+ 223 + 213

So x - 2 = 223 + 213

Now cubing on both sides, we get

=> x3-8-6x2+12x = 4 + 2 + 6(x-2)

Therefore, x3-6x2+6x = -6 + 8 = 2

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.

A prime number is a whole number greater than 1 whose only factors are 1 and itself.

Factors of 5 are 1, 5

Factors of 11 are 1, 11

Factors of 21 are 1, 3, 7, 21

Factors of 37 are 1, 37.

Hence, according to the definition of a prime number, 21 is not a prime number as it has more than two factors.

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.