Question

Alex and ben go to a cafe with some friends. Alex buys 4 cups of coffee and 3cups of tea. He pays a total of £6.95. Ben buys 5 cups of coffee and 2 cups of tea. He pays a total of £7.20 Work out the cost of each cup of coffee and the cost of each cup of tea

Answer 1

c - the cost of one cup of coffee
t - the cost of one cup of tea
1. (4c + 3t=6.95)*2 -----> 8c+6t=13.90 (1)
(5c + 2t =7.20) *(-3) ---->-15c-6t=-21.60 (2)

2. Add equation (1) and (2)
-7c= - 7.70, c=1.10 Cup of Coffee £ 1.10
3. substitute 1.10 into the first equation
4c + 3t=6.95, 4*1.10 + 3t=6.95, 3t = 6.95-4.40 =2.55, t= £ 0.85 cup of tea