Answer:
adult cost £7, child cost £2
Explanation:
let a represent an adult and c a child , then
2a + 3c = 20 → (1)
a + 4c = 15 → (2)
Multiplying (2) by - 2 and adding to (1) will eliminate a
- 2a - 8c = - 30 → (3)
Add (1) and (3) term by term to eliminate a, that is
- 5c = - 10 ( divide both sides by - 5 )
c = 2
Substitute c = 2 into either of the 2 equations and evaluate for a
Substituting into (2)
a + 4(2) = 15
a + 8 = 15 ( subtract 8 from both sides )
a = 7
The cost of an adult ticket is £7 and a child ticket is £2