PSLE
Jade had jigsaw puzzles for sale. In the morning, she sold ¹₅ of the jigsaw puzzles. In the afternoon, she sold ²₇ of the remaining jigsaw puzzles. After that, there were 100 jigsaw puzzles left. How many jigsaw puzzles did Jade have at first?
Fraction of jigsaw puzzles left after selling in the morning
= 1 - ¹₅
= ⁴₅

Fraction of the remaining jigsaw puzzles after selling in the afternoon
= 1 - ²₇
= ⁵₇

⁵₇ of remaining jigsaw puzzles = 100
¹₇ of remaining jigsaw puzzles = 100 ÷ 5 = 20
⁷₇ of remaining jigsaw puzzles = 7 x 20 = 140

⁴₅ of total jigsaw puzzles = 140
¹₅ of the total jigsaw puzzles = 140 ÷ 4 = 35
⁵₅ of the total jigsaw puzzles = 5 x 35 = 175

Number of jigsaw puzzles at first = 175

Answer(s): 175