Esther bought some Social Science books at $17 each. She also bought an equal number of History books at a different price. The average price of one Social Science and one History book was $10. Esther paid $126 more for the Social Science books than the History books.
- What was the cost of one History book?
- How many Social Science books did Esther buy?
|
Social Science |
History |
More |
Number |
1 u |
1 u |
|
Value |
$17 |
$3 |
|
Total value |
17 u |
3 u |
$126 |
(a)
Price of one History book
= 2 x 10 - 17
= 20 - 17
= $3
Amount that Esther paid more for Social Science books than History books
= 17 u - 3 u
= 14 u
14 u = 126
1 u = 126 ÷ 14 = 9
Number of Social Science books that Esther bought
= 1 u
= 9
Answer(s): (a) $3; (b) 9