Question

After 15 years Mary age will be four times of het present age find her present age

Answer 1

Let Mary's present age=x
Her age after 15 years= x+15
Acc to question,
x+15=4x
4x-x=15
3x=15
x=5
Therefore Mary's present age is 5

Answer 2

Let her present age be = y
Her age after 15 years = (y + 15) or 4y

According to question, equation formed will be:

4y      =    y + 15
4y - y =   15
3y      =   15
y        =   15/3
y        =   5

Therefore, Mary’s present age is 5 years.