PSLE
Wendy and Vincent bought paintings at the prices shown below.

3 Large paintings for $8
4 Small paintings for $6

1. Wendy bought an equal number of large and small paintings. She spent $28 more on the large ones. How many paintings did she buy altogether?
2. Vincent spent an equal amount of money on the large and small paintings. What fraction of the paintings he bought were large?

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

Cost of 3 large paintings = $8
Cost of 12 large paintings = 4 x 8 = $32

Cost of 4 small paintings = $6
Cost of 12 small paintings = 3 x 6 = $18

Difference in the cost of buying 12 small paintings and 12 large paintings
= 32 - 18
= $14

Number of sets of paintings
= 28 ÷ 14
= 2

Number of paintings that Wendy bought
= 2 x 2 x 12
= 48

(b)
Vincent spent an equal amount of money on the large and small paintings.  Make the amount of money spent on the large and small paintings the same.
LCM of 8 and 6 is 24.

Number of large paintings that Vincent bought
= 3 x (24 ÷ 8)
= 3 x 3
= 9

Number of the small paintings that Vincent bought
= 4 x (24 ÷ 6)
= 4 x 4
= 16

Fraction of the paintings that Vincent bought that were large
= ⁹_{9 + 16}
= ⁹₂₅

Answer(s): (a) 48; (b) ⁹₂₅