Question

Maths:
1. The ages of Rahul and Ramya are in the ratio 5:7 four years later,the sum of their ages will be 56years.what are their present age​

Answer 1

Solution :

Let the present ages of Rahul and Haroon be 5x years and 7x years respectively.

Four years later

=> Age of Rahul = (5x + 4) years

=> Age of Haroon = (7x + 4) years

Four years later the sum of their ages will be 56 years.

=> (5x + 4) + (7x + 4) = 56

=> 12x + 8 = 56

=> 12x = 56 - 8

Transposing 8 to RHS

=> 12x = 48

=> x = 48/12

=> x = 4

Dividing both sides by 12

=> 5x = 5 x 4 = 20

=> 7x= 7 x 4 = 28

=> Hence, their present ages are 20 years and 28 years

Answer 2

Step-by-step explanation:

let rahul's current age be x

let ramya's current age be y

given,

=x/y =5/7

so, 7x=5y . i. e, 7x-5y=0----eqn.1

after four years,

there age will be

rahul's age =(x+4)

ramya's age =(y+4)

so sum of their age will be

=(x+4) +(y+4)= x+y+8=56

=x+y+8-56=0

x+y-48=0------eqn.2

by eqn. 1 and eqn. 2,

7x-5y=0

x+y-46=0

multiplying eqn. 2 by 5,

then

7x-5y=0

5x+5y-240=0

cancelling '5y' ,

=12x-240=0

=12x=240

=x=20

so, x is equal to 20..

substituting x in eqn.1,

.i.e,

=7(20)-5y=0

=140=5y

= y=28

so, y is equal to 28..

so therefore, current age of rahul is 20 and current age of ramya is 28..