Fill in the blanks.
Adam spends
18 of his money on 2 erasers and 4 marbles.
Each marble costs four times as much as each eraser.
Let the price of 1 eraser be 1 u.
- Cost of 1 marble = _____ u
- Amount that Adam has spent = _____ u
- Amount that Adam has left = _____ u
- Amount that Adam has at first = _____ u
(a)
Change X times into units.
Cost of 1 eraser = 1 u
Cost of 1 marble = 4 x 1 u = 4 u
(b)
Amount that Adam has spent
= 2 x 1 u + 4 x 4 u
= 2 u + 16 u
= 18 u
(c)
Fraction of the money he has left
= 1 -
18 =
78 18 of his money = 18 u
78 of his money = 7 x 18 u = 126 u
Amount that Adam has left = 126 u
(d)
Amount that Adam has at first
= 18 u + 126 u
= 144 u
Answer(s): (a) 4; (b) 18; (c) 126; (d) 144