Question 94
The sum of the ages of brother and sister at present is 21. Five years ago the product of their ages was 28. What is the age of the brother and the sister?
Solution
Let the age of brother = $$x$$ years and sister's age = $$(21-x)$$ years
Product of their ages 5 years ago = $$(x-5)(21-x-5) = 28$$
=> $$(x-5)(16-x)=28$$
=> $$16x-x^2-80+5x=28$$
=> $$x^2-21x+108=0$$
=> $$x^2-9x-12x+108=0$$
=> $$x(x-9)-12(x-9)=0$$
=> $$(x-12)(x-9)=0$$
=> $$x=12,9$$
$$\therefore$$ Ages of brother and sister are 12 and 9
=> Ans - (A)
Need AI Help?
Create a FREE account and get:
- Free SSC Study Material - 18000 Questions
- 230+ SSC previous papers with solutions PDF
- 100+ SSC Online Tests for Free
