Question

The cost of 3 cheese sandwiches and 2 bottles of water is £7.80. The cost of 5 cheese sandwiches and 4 bottles of water is £14.20. What is the cost of: (a) one cheese sandwich? (b) one bottle of water?

Answer 1

sandwiches is £1.8

bottle water = £1.2

Explanation:

Given data

let cheese sandwiches be x

and bottle water be y

3x+2y= 7.8------------1

5x+4y= 14.20---------2

solve 1 and 2

3x+2y= 7.8------------1*5

5x+4y= 14.20---------2*3

15x+10y= 39

- 15x+12y= 42.6

-2y = -3.6

y= 3.6/2

x=1.8

Put x= 1.8 in 1

3(1.8)+2y= 7.8

5.4+2y= 7.8

2y= 7.8-5.4

2y=2.4

y= 2.4/2

y= 1/2

Hence cheese sandwiches is £1.8

bottle water = £1.2