PSLE
Nicole and Jack bought durians at the prices shown below.

4 Large durians for $10
7 Small durians for $4

1. Nicole bought an equal number of large and small durians. She spent $216 more on the large ones. How many durians did she buy altogether?
2. Jack spent an equal amount of money on the large and small durians. What fraction of the durians he bought were large?

(a)
Number of large and small durians that Nicole bought is the same. Make the number of large and small durians the same. LCM of 4 and 7 is 28.

Cost of 4 large durians = $10
Cost of 28 large durians = 7 x 10 = $70

Cost of 7 small durians = $4
Cost of 28 small durians = 4 x 4 = $16

Difference in the cost of buying 28 small durians and 28 large durians
= 70 - 16
= $54

Number of sets of durians
= 216 ÷ 54
= 4

Number of durians that Nicole bought
= 4 x 2 x 28
= 224

(b)
Jack spent an equal amount of money on the large and small durians.  Make the amount of money spent on the large and small durians the same.
LCM of 10 and 4 is 20.

Number of large durians that Jack bought
= 4 x (20 ÷ 10)
= 4 x 2
= 8

Number of the small durians that Jack bought
= 7 x (20 ÷ 4)
= 7 x 5
= 35

Fraction of the durians that Jack bought that were large
= ⁸_{8 + 35}
= ⁸₄₃

Answer(s): (a) 224; (b) ⁸₄₃