The ratio between the number of males and females in a college is 21:22. If the number of males are increased by 20% and the number of female increased by 30%. What is new ratio of males and females in the college?

a) 127:143
b) 125:143
c) 128:143
d) 126:143

Ans : d) 126:143

UP Police SI Exam Paper : Mathematics

Solution

Let the initial number of males be ( 21x ) and the initial number of females be ( 22x ), where ( x ) is a common multiplier.

Step 1: Calculate the increased number of males.

The number of males is increased by 20%, so the new number of males becomes:
New number of males =

Step 2: Calculate the increased number of females.

The number of females is increased by 30%, so the new number of females becomes:
New number of females =

Step 3: Calculate the new ratio.

The new ratio of males to females is:
New ratio =

New ratio =
Thus, the new ratio of males to females is ( 126:143 ).