Fill in the blanks.
Amadeus spends
18 of his money on 4 cards and 4 erasers.
Each eraser costs thrice as much as each card.
Let the price of 1 card be 1 u.
- Cost of 1 eraser = _____ 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 card = 1 u
Cost of 1 eraser = 3 x 1 u = 3 u
(b)
Amount that Amadeus has spent
= 4 x 1 u + 4 x 3 u
= 4 u + 12 u
= 16 u
(c)
Fraction of the money he has left
= 1 -
18 =
78 18 of his money = 16 u
78 of his money = 7 x 16 u = 112 u
Amount that Amadeus has left = 112 u
(d)
Amount that Amadeus has at first
= 16 u + 112 u
= 128 u
Answer(s): (a) 3; (b) 16; (c) 112; (d) 128