Question

a girl is twice as a old as her sister. five years hence, the product of their ages (in years)
will be 375. find their present ages

Answer 1

Answer:

present age of that girl = 2x

present age of her sister = x

after five years -

age of that girl= 2x + 5

age of her sister = x + 5

product of their ages = 375

equation formed =

( 2x + 5)(x + 5) = 375

2x^2 + 10x + 5x + 25 = 375

2x^2 + 15 x - 350 = 0

here we will use the quadratic formula to find the roots

shown in the image

since x cannot be negative hence x = 10

age of that girl= 20

her sister = 10