Fill in the blanks.
Amadeus spends
18 of his money on 5 coins and 5 buttons.
Each button costs thrice as much as each coin.
Let the price of 1 coin be 1 u.
- Cost of 1 button = _____ u
- Amount that Amadeus has spent = _____ u
- Amount that Amadeus has left = _____ u
- Amount that Amadeus has at first = _____ u
(a)
Change X times into units.
Cost of 1 coin = 1 u
Cost of 1 button = 3 x 1 u = 3 u
(b)
Amount that Amadeus has spent
= 5 x 1 u + 5 x 3 u
= 5 u + 15 u
= 20 u
(c)
Fraction of the money he has left
= 1 -
18 =
78 18 of his money = 20 u
78 of his money = 7 x 20 u = 140 u
Amount that Amadeus has left = 140 u
(d)
Amount that Amadeus has at first
= 20 u + 140 u
= 160 u
Answer(s): (a) 3; (b) 20; (c) 140; (d) 160