Fill in the blanks.
Alfred spends
15 of his money on 5 marbles and 5 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 Alfred has spent = _____ u
- Amount that Alfred has left = _____ u
- Amount that Alfred 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 Alfred has spent
= 5 x 1 u + 5 x 5 u
= 5 u + 25 u
= 30 u
(c)
Fraction of the money he has left
= 1 -
15 =
45 15 of his money = 30 u
45 of his money = 4 x 30 u = 120 u
Amount that Alfred has left = 120 u
(d)
Amount that Alfred has at first
= 30 u + 120 u
= 150 u
Answer(s): (a) 5; (b) 30; (c) 120; (d) 150