Roshel bought some Social Science books at $13 each. She also bought an equal number of Malay books at a different price. The average price of one Social Science and one Malay book was $10. Roshel paid $72 less for the Malay books than the Social Science books.
- What was the cost of one Malay book?
- How many Social Science books did Roshel buy?
|
Social Science |
Malay |
Less |
Number |
1 u |
1 u |
|
Value |
$13 |
$7 |
|
Total value |
13 u |
7 u |
$72 |
(a)
Price of one Malay book
= 2 x 10 - 13
= 20 - 13
= $7
Amount that Roshel paid less for Malay books than Social Science books
= 13 u - 7 u
= 6 u
6 u = 72
1 u = 72 ÷ 6 = 12
Number of Social Science books that Roshel bought
= 1 u
= 12
Answer(s): (a) $7; (b) 12