PSLE Betty and Bobby bought durians at the prices shown below.
4 Large durians for $10
5 Small durians for $4
- Betty bought an equal number of large and small durians. She spent $102 more on the large ones. How many durians did she buy altogether?
- Bobby spent an equal amount of money on the large and small durians. What fraction of the durians he bought were small?
(a)
Number of large and small durians that Betty bought is the same. Make the number of large and small durians the same. LCM of 4 and 5 is 20.
Cost of 4 large durians = $10
Cost of 20 large durians = 5 x 10 = $50
Cost of 5 small durians = $4
Cost of 20 small durians = 4 x 4 = $16
Difference in the cost of buying 20 small durians and 20 large durians
= 50 - 16
= $34
Number of sets of durians
= 102 ÷ 34
= 3
Number of durians that Betty bought
= 3 x 2 x 20
= 120
(b)
Bobby 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 Bobby bought
= 4 x (20 ÷ 10)
= 4 x 2
= 8
Number of the small durians that Bobby bought
= 5 x (20 ÷ 4)
= 5 x 5
= 25
Fraction of the durians that Bobby bought that were small
=
258 + 25 =
2533 Answer(s): (a) 120; (b)
2533