Respuesta :

SOLUTION:

Let the Gold star awarded be "g" and books read be "b"

7 g = 21 b

1 g = 21/7 = 3 b

14 g = 3 X 14 = 42 b

21 g = 3 X 21 = 63 b

28 g = 3 X 28 = 84 b

35 g = 3 X 35 = 105 b