Pei Chun Public Sch 2007 PSLE Math Prelim Q40

Kavita had 50% fewer erasers than Mark. After Mark gave 15 of his erasers to Kavita, Kavita had 40% fewer erasers than Mark. How many erasers did Kavita have at first?

Solution



Kativa has 30 more, while Mark has 15 less. Hence, Kativa will have 45 more than Mark.

45 ----- 120% - 100%
45 ----- 20%
10% ----- 45% divided by 2 = 22.5%

Kativa at first ----- 60% -15
= (6 x 22.5) - 15
= 135 – 15
= 120

Answer: Kativa had 120 erasers at first.