Question

a boy is Y years old his sister was thrice as old as he is the sum of their ages is 24 how old is the boy​

Answer 1

${\huge {\underline {\bf {\purple {Question}}}}}$

A boy is "y" years old. His sister is thrice as old as he is the sum of their ages is 24. How old is the boy ?

${\huge {\underline {\bf {\purple {Answer}}}}}$

Given :-

• A boy is "y" years old.
• His sister is thrice as old as he is the sum of their ages is 24.

To Find :-

• The age of the boy.

Solution :-

According to the question,

The age of his sister will be "3y" years and the sum of their ages is 24.

$~~~~$ $\rightarrowtail {\sf {y + 3y = 24}}$

$~~~~$$\rightarrowtail {\sf {4y = 24}}$

$~~~~$$\rightarrowtail {\sf {y = {\dfrac {{\cancel{{24}}^{6}}}{{\cancel{{4}}^{1}}}}}}$

$~~~~$${\red \rightarrowtail {\red {\sf {y = 6}}}}$

Therefore,

${\sf {The~ age~ of~ the~ boy = y = 6~ years}}$

${\sf {The~ age~ of~ his~ sister = 3y = 3 \times 6 = 18~ years.}}$