PSLE
Shiyun and Ben bought towels at the prices shown below.

3 Large towels for $7
4 Small towels for $5

1. Shiyun bought an equal number of large and small towels. She spent $52 more on the large ones. How many towels did she buy altogether?
2. Ben spent an equal amount of money on the large and small towels. What fraction of the towels he bought were large?

(a)
Number of large and small towels that Shiyun bought is the same. Make the number of large and small towels the same. LCM of 3 and 4 is 12.

Cost of 3 large towels = $7
Cost of 12 large towels = 4 x 7 = $28

Cost of 4 small towels = $5
Cost of 12 small towels = 3 x 5 = $15

Difference in the cost of buying 12 small towels and 12 large towels
= 28 - 15
= $13

Number of sets of towels
= 52 ÷ 13
= 4

Number of towels that Shiyun bought
= 4 x 2 x 12
= 96

(b)
Ben spent an equal amount of money on the large and small towels.  Make the amount of money spent on the large and small towels the same.
LCM of 7 and 5 is 35.

Number of large towels that Ben bought
= 3 x (35 ÷ 7)
= 3 x 5
= 15

Number of the small towels that Ben bought
= 4 x (35 ÷ 5)
= 4 x 7
= 28

Fraction of the towels that Ben bought that were large
= ¹⁵_{15 + 28}
= ¹⁵₄₃

Answer(s): (a) 96; (b) ¹⁵₄₃