Fill in the blanks.
Ali spends
18 of his money on 5 erasers and 2 buttons.
Each button costs twice as much as each eraser.
Let the price of 1 eraser be 1 u.
- Cost of 1 button = _____ u
- Amount that Ali has spent = _____ u
- Amount that Ali has left = _____ u
- Amount that Ali has at first = _____ u
(a)
Change X times into units.
Cost of 1 eraser = 1 u
Cost of 1 button = 2 x 1 u = 2 u
(b)
Amount that Ali has spent
= 5 x 1 u + 2 x 2 u
= 5 u + 4 u
= 9 u
(c)
Fraction of the money he has left
= 1 -
18 =
78 18 of his money = 9 u
78 of his money = 7 x 9 u = 63 u
Amount that Ali has left = 63 u
(d)
Amount that Ali has at first
= 9 u + 63 u
= 72 u
Answer(s): (a) 2; (b) 9; (c) 63; (d) 72