Question

the present ages of three colleagues are in the proportion 3:5:7. four years ago, the sum of their ages was 48. find the present ages(in years)
15,25 and 35 years
9 , 15 and 21 years
12, 20 , and 28 years
none of these​

Answer 1

GIVEN :–

• The present ages of three colleagues are in the proportion 3:5:7.

• Four years ago, the sum of their ages was 48.

TO FIND :–

• Present ages = ?

SOLUTION :–

• Let their ages = 3x , 5x , 7x

▪︎ According to the question –

=> Four years ago, the sum of their ages was 48.

• Four year ago their ages ➪ (3x - 4) , (5x - 4) , (7x - 4)

=> (3x - 4) + (5x - 4) + (7x - 4) = 48

=> 15x - 12 = 48

=> 15x = 48 + 12

=> 15x = 60

=> x = 4

• Hence –

=> Their ages = 3(4) , 5(4) , 7(4)

=> Their ages = 12 , 20 , 28

Answer 2

GIVEN :-

• The present ages of three colleagues are in the proportion 3:5:7.

•And four years ago, the sum of their ages was 48.

TO FIND :-

• Present ages(in years) = ?

SOLUTION :-

=> Let their ages = 3R , 5R , 7R

•Four years ago, the sum of their ages was 48.

=> (3R - 4) + (5R - 4) + (7R - 4) = 48

=> 15R - 12 = 48

=> 15R = 48 + 12

=> 15R = 60

=> R = 4

• Therefore :-

=> Their ages = 3R , 5R , 7R

=> Their ages = 3(4) , 5(4) , 7(4) ( °.° R = 4 )

=> Their ages = 12 , 20 , 28 .