Small coconuts	Medium coconuts	Large coconuts
$2	$8	$9

Ben had some coconuts in 3 sizes. The number of medium coconuts was four times the number of large coconuts. The number of large coconuts were five times the number of small coconuts. He sold all the small and medium coconuts. He received $180 from selling ²₅ of the large coconuts.

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

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

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

	Small coconuts	Medium coconuts	Large coconuts
Before	1 u	20 u	5 u
Change	- 1 u	- 20 u	- 2 u
After	0	0	3 u

Number of large coconuts that Ben sold
= ²₅ x 5 u
= 2 u

	Small coconuts	Medium coconuts	Large coconuts
Number	1 u	20 u	2 u
Value	$2	$8	$9
Total value	2 u	160 u	18 u

Amount that Ben received from selling of ²₅ of the large coconuts = 18 u
18 u = 180

1 u = 180 ÷ 18 = 10

Number of large coconuts at first
= 5 u
= 5 x 10
= 50

(b)
Amount that Ben collected less from selling the small coconuts than the medium coconuts
= 160 u - 2 u
= 158 u
= 158 x 10
= $1580

Answer(s): (a) 50; (b) $1580