Small durians	Medium durians	Large durians
$2	$5	$6

Oscar had some durians in 3 sizes. The number of medium durians was four times the number of large durians. The number of large durians were five times the number of small durians. He sold all the small and medium durians. He received $72 from selling ¹₅ of the large durians.

1. How many large durians did he have at first?
2. How much less did he collect from selling the small durians than the medium durians?

Small durians	Medium durians	Large durians
	4x5	1x5
1x1		5x1
1 u	20 u	5 u

(a)
The number of large durians is the repeated identity. Make the number of large durians the same.  LCM of 1 and 5 is 5.

	Small durians	Medium durians	Large durians
Before	1 u	20 u	5 u
Change	- 1 u	- 20 u	- 1 u
After	0	0	4 u

Number of large durians that Oscar sold
= ¹₅ x 5 u
= 1 u

	Small durians	Medium durians	Large durians
Number	1 u	20 u	1 u
Value	$2	$5	$6
Total value	2 u	100 u	6 u

Amount that Oscar received from selling of ¹₅ of the large durians = 6 u
6 u = 72

1 u = 72 ÷ 6 = 12

Number of large durians at first
= 5 u
= 5 x 12
= 60

(b)
Amount that Oscar collected less from selling the small durians than the medium durians
= 100 u - 2 u
= 98 u
= 98 x 12
= $1176

Answer(s): (a) 60; (b) $1176