A confectionery sells cranberry sandwiches and chocolate chip sandwiches.

Cranberry sandwiches	Chocolate chip sandwiches
7 for $2.70	5 for $3.10

Yoko bought an equal number of cranberry sandwiches and chocolate chip sandwiches. She paid $49.20 more for the chocolate chip sandwiches and the cranberry sandwiches.

1. How many sandwiches did she buy?
2. How much did she spend altogether?

(a)
Yoko bought an equal number of cranberry sandwiches and chocolate chip sandwiches.  Make the number of cranberry sandwiches and chocolate chip sandwiches the same.  LCM of 7 and 5 is 35.

Number of sets of 7 in 35
= 35 ÷ 7
= 5

Cost of 1 set of 35 cranberry sandwiches
= 5 x 2.70
= $13.50

Number of sets of 5 in 35
= 35 ÷ 5
= 7

Cost of 1 set of 35 chocolate chip sandwiches
= 7 x 3.10
= $21.70

Amount that Yoko paid more for 1 set of 35 chocolate chip sandwiches than 1 set of 35 cranberry sandwiches
= 21.70 - 13.50
= $8.20

Number of sets of $8.20
= 49.20 ÷ 8.20
= 6

Total number of sandwiches in 1 set of 35 chocolate chip sandwiches and 35 cranberry sandwiches
= 2 x 35
= 70

Number of sandwiches that Yoko bought
= 6 x 70
= 420

(b)
Cost of sandwiches in 1 set of 35 chocolate chip sandwiches and 35 cranberry sandwiches
= 13.50 + 21.70
= $35.20

Total amount that Yoko spent altogether
= 6 x 35.20
= $211.20

Answer(s): (a) 420 ; (b) $211.20