In a supermarket, the prices of pastries are listed as follow:

Pastry Prices
Sandwich	$1
Tart	$5
Puff	$4

The ratio of the number of sandwiches sold to the number of tarts sold was 5 : 3. The ratio of the number of puffs sold to the number of tarts sold was 7 : 5. The supermarket collected $50 more on the sales of puffs than the sales of sandwiches.

1. How many sandwiches were sold?
2. How much did the supermarket collect from the sales of the pastries?

Sandwiches	Tarts	Puffs
5x7	3x7
	7x3	5x3
35 u	21 u	15 u

	Sandwiches	Tarts	Puffs
Number	35 u	21 u	15 u
Value	1	5	4
Total value	35 u	105 u	60 u

(a)
The number of tarts sold is repeated.  Make the number of tarts the same.  LCM of 3 and 7 is 21.

Amount that the supermarket collected more from the sales of the puffs than the sandwiches
= 60 u - 35 u
= 25 u

25 u = 50

1 u = 50 ÷ 25 = 2

Number of sandwiches that the cafe sold
= 35 u
= 35 x 2
= 70

(b)
Amount that the supermarket collected from the sales of the pastries
= 35 u + 105 u + 60 u
= 200 u
= 200 x 2
= $400

Answer(s): (a) 70; (b) $400