Fill in the blanks.
Adam spends
12 of his money on 4 marbles and 3 erasers.
Each eraser costs five times as much as each marble.
Let the price of 1 marble be 1 u.
- Cost of 1 eraser = _____ 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 marble = 1 u
Cost of 1 eraser = 5 x 1 u = 5 u
(b)
Amount that Adam has spent
= 4 x 1 u + 3 x 5 u
= 4 u + 15 u
= 19 u
(c)
Fraction of the money he has left
= 1 -
12 =
12 12 of his money = 19 u
12 of his money = 1 x 19 u = 19 u
Amount that Adam has left = 19 u
(d)
Amount that Adam has at first
= 19 u + 19 u
= 38 u
Answer(s): (a) 5; (b) 19; (c) 19; (d) 38