Mathematics 2009 JAMB Past Questions - Question 6: A student spent 1/5 of his allowances on books ,1/3 of the remainder on food and kept the rest for contingencies .What fraction was kept?

Correct Answer

B

Explanation

spent 1/5 on books remaining 4/15spent 1/3 of 4/5 on food = 4/5 x1/3 = 1/15therefore 4/5 - 4/15= 12 - 4 /15 = 8/15Let's assume the student's allowance is represented by the whole number 1.The student spent 1/5 of the allowance on books. This means the student spent (1/5) * 1 = 1/5 of the allowance on books.The remainder after spending on books is (1 - 1/5) = 4/5.Next, the student spent 1/3 of the remainder on food. This means the student spent (1/3) * (4/5) = 4/15 of the allowance on food.The remaining fraction after spending on food is (4/5 - 4/15) = 8/15.Therefore, the student kept 8/15 of the allowance for contingencies.