Question

137. The ratio of the ages of the father and the
son at present is 6: 1. After 5 years the ratio will
become 7: 2. The present age of the son is:
a) 5 years
b) 4 years
c) 6 years
d) 9 years​

Answer 1

Answer:

let the ratio of present age of father and son be 6x and X

age after 5 yrs

father's age =(6x+5)

son's age=(X + 5)

A/q

(6x + 5)/(X + 5) =7/2

or,2(6x+5) =7(X+5)

or,12x+10=7x+35

or,5x=25

or,X=5

Answer 2

$\huge\underbrace\pink{Answer}$

Given :-

• Ratio of the ages of father and son at present is 6 : 1

• After 5 years there ratio will be 7 : 2

To Find :-

• The Present age of the son

Solution :-

➣ Let the present age of father and son be 6x and x

➣ Then, After 5 years the age of the father will be (6x+5)years

➣ And, After 5 years the age of the son will be (x+5)years

$\therefore\sf{ 6x + 5 \: : \: x + 5 = 7:2 }$

By solving this equation, we get

$\implies\sf{ \dfrac{6x + 5}{x + 5} = \dfrac{7}{2} }$

$\implies\sf{2(6x + 5) = 7( x + 5)}$

$\implies\sf{12x + 10 = 7x + 35}$

$\implies\sf{12x - 7x = 35 - 10}$

$\implies\sf{5x = 25}$

$\implies\sf{x = \dfrac{\cancel{25}^{5} } {\cancel{5} }}$

$\implies\sf\pink{x = 5}$

Hence, The present age of the son is Option - A (5 years)