Min's shop sold coats and shirts. The coats were sold at $80 each and each shirt was sold at ¹₂ of the price of each coat. Min sold ¹₅ of the items on the first day and collected $4320. ⁴₅ of the items sold on the first day were coats.

1. How many shirts were sold on the first day?
2. What was the total number of items left after the first day?

(a)

Sold		Unsold	Total
1x5		4x5	5x5
Coats	Shirts
4x1	1x1
4 u	1 u	20 u	25 u

The total number of coats and shirts sold is repeated.  Make the total number of coats and shirts sold the same.  LCM of 5 and 1 is 5.

	Coats	Shirts	Total
Number	4 u	1 u	5 u
Value	$80	$40
Total value	320 u	40 u	360 u

Cost of each shirt
= ¹₂ x 80
= $40

Total amount collected from selling the coats and the shirts on the first day
= 320 u + 40 u
= 360 u

360 u = 4320

1 u = 4320 ÷ 360 = 12

Number of shirts sold on the first day
= 1 u
= 12

(b)
Total number of items left after the first day
= 20 u
= 20 x 12
= 240

Answer(s): (a) 12; (b) 240