PSLE
Nora had jigsaw puzzles for sale. In the morning, she sold ⁴₇ of the jigsaw puzzles. In the afternoon, she sold ¹₅ of the remaining jigsaw puzzles. After that, there were 36 jigsaw puzzles left. How many jigsaw puzzles did Nora have at first?
Fraction of jigsaw puzzles left after selling in the morning
= 1 - ⁴₇
= ³₇

Fraction of the remaining jigsaw puzzles after selling in the afternoon
= 1 - ¹₅
= ⁴₅

⁴₅ of remaining jigsaw puzzles = 36
¹₅ of remaining jigsaw puzzles = 36 ÷ 4 = 9
⁵₅ of remaining jigsaw puzzles = 5 x 9 = 45

³₇ of total jigsaw puzzles = 45
⁴₇ of the total jigsaw puzzles = 45 ÷ 3 = 15
⁷₇ of the total jigsaw puzzles = 7 x 15 = 105

Number of jigsaw puzzles at first = 105

Answer(s): 105