Ratio and Proportion MCQs

Two numbers are respectively 20% and 50% more than a third number. The ratio of the two numbers is :__________?

by
A. 2 : 5
B. 3 : 5
C. 4 : 5
D. 6 : 7
✅ The correct answer is option C. 4 : 5.
Let the third number be x.

Then, first number = 120% of x = 120x/100 = 6x/5 second numbet = 150% of x = 150x/100 = 3x/2 Ratio of first two numbers = 6x/5 : 3x/2 =12x : 15x = 4 : 5.

The ratio of the number of boys and girls in a college is 7 : 8. If the percentage iikcrease in the number of boys and girls be 20% and 10% respectively, what will be the new ratio ?

by
A. 8 : 9
B. 17 : 18
C. 21 : 22
D. Cannot be determined
✅ The correct answer is option C. 21 : 22.
Originally, let the number of boys and girls in the college be 7x and 8x respectively. Their increased number is (120% of 7x) and (110% of 8x), i . e . ( 120/100 X 7x ) and ( 110/100 X 8x ) i . e . 42x/5 and 44x/5 Required ratio = 42x/5 : 44x/5 = 21 : 22

Seats for Mathematics, Physics and Biology in a school are in the ratio 5 : 7 : 8. There is a proposal to increase these seats by 40%, 50% and 75% respectively. What will be the ratio of increased seats ?

by
A. 2 : 3 : 4
B. 6 : 7 : 8
C. 6 : 8 : 9
D. None of these
✅ The correct answer is option A. 2 : 3 : 4.
5:7:8 = 50:70:80

50*140/100=70 ; 70*150/100=105 ; 80*175/100=140

70: 105: 140 or

14: 21: 28 or

2: 3: 4