PSLE
Jaslyn had flying saucers for sale. In the morning, she sold ²₅ of the flying saucers. In the afternoon, she sold ²₉ of the remaining flying saucers. After that, there were 21 flying saucers left. How many flying saucers did Jaslyn have at first?
Fraction of flying saucers left after selling in the morning
= 1 - ²₅
= ³₅

Fraction of the remaining flying saucers after selling in the afternoon
= 1 - ²₉
= ⁷₉

⁷₉ of remaining flying saucers = 21
¹₉ of remaining flying saucers = 21 ÷ 7 = 3
⁹₉ of remaining flying saucers = 9 x 3 = 27

³₅ of total flying saucers = 27
²₅ of the total flying saucers = 27 ÷ 3 = 9
⁵₅ of the total flying saucers = 5 x 9 = 45

Number of flying saucers at first = 45

Answer(s): 45