Andy had some erasers. He gave ²₃ of his erasers to Archie and bought 4 new erasers. After that, he gave ³₅ of his remaining erasers to his cousin and bought another 7 new erasers. In the end, Andy had 27 erasers.

1. How many erasers did Andy give to his cousin?
2. How many erasers did Andy have at first?

(a)
Fraction of  his remaining erasers after he gave to his cousin
= 1 - ³₅
= ²₅

²₅ of his remaining erasers = 27 - 7 = 20
¹₅ of his remaining erasers = 20 ÷ 2 = 10
³₅ of his remaining erasers = 3 x 10 = 30

Number of erasers that Andy gave to his cousin = 30

(b)
⁵₅ of his remaining erasers = 5 x 10 = 50

Fraction of his total erasers after he gave to Archie
= 1 - ²₃
= ¹₃

¹₃ of his total erasers = 50 - 4 = 46
³₃ of his total erasers = 3 x 46 = 138

Number of erasers that Andy had at first = 138 

Answer(s): (a) 30; (b) 138