Question

After 15 years , Mary's age will be four times of her present age. Find her present age.​

Answer 1

Here is Your Answer :-

=> Let the Present Age of Mary be ‘x’

=> After 15 years her age will be,

—> 4x = x + 15
—> 4x - x = 15
—> 3x = 15
—> x = 15/3
—> x = 5

Hence the Present age of Mary is 5 years..


Hope it Helps You…

Answer 2

✰Assumption༄

➡ Consider the present age of Mary be m years

✰Now༄

According to condition given in question ,

➡ After 15 years Mary's age

$\rm \implies \: (m + 15) \: years$

which is four times of her present age

$\rm \implies \: 4 \: (m)$

✰Then༄

$\longrightarrow\bigstar \: \: \sf\boxed{\bold{\green{ 4 \: (m) = m + 15}}}\: \: \: \bigstar$

$\longrightarrow\bigstar \: \: \sf\boxed{\bold{\pink{4 \: m - m = 15 }}}\: \: \: \bigstar$

$\longrightarrow\bigstar \: \: \sf\boxed{\bold{\red{3 \: m = 15}}}\: \: \: \bigstar$

$\implies\bigstar \: \: \sf\boxed{\bold{\orange{m = \dfrac{15}{3} }}}\: \: \: \bigstar$

$\implies\bigstar \: \: \sf\boxed{\bold{\blue{5 \: years}}}\: \: \: \bigstar$

$\rm \therefore \: Thus \: Mary's \: present \: age$

$\implies\bigstar \: \: \sf\boxed{\bold{\gray{m = 5 \: years}}}\: \: \: \bigstar$