Question

The present age of two brothers are in the ratio of 3: 4 five year back their ages were in the ratio of 5: 7 find their present ages.

Answer 1

Answer:

Let the age of the elder brother be x and older brother be y

x/y=3/4

=>4x=3y           -(1)

x-5/y-5=5/7

=>7(x-5)=5(y-5)

=>7x-35=5y-25

=>7x=5y+10    -(2)

Substitution equation 1 in 2

7(3y/4)=5y+10

21y=20y+40

y=40

we know 4x=3y

4x=3(40)

x=30

Hence the ages were 30,40

Answer 2

Let 3x and 4x be the ages of the brothers[present ]

5years before, younger boy age=3x-5

elder boy age=4x-5

3x-5/4x-5=5/7

7(3x-5)=5(4x-5)

21x-35=20x-25

21x-20x= -25+35

X=10years

younger boy age=3x=3*10=30

elder boy age =4x=4*10=40

Hope it Helps