Question

The product of a girl's age five years ago and her age 3 years later is 105. Find her present age.

Answer 1

Let the present age of the Girl be G year. Then, as per the question description, 

(G - S)(G + 3) = 105 

⇒ G² - 2G - 120 = 0 

⇒  G² -12G + 10G - 120 = 0 

⇒  G (G - 12) +10 (G - 12) = 0  

⇒  G=12 , G = -10 (Agecannotbe negative) 

⇒  G=12 Years