Answer:
£107.95
Explanation:
We can use a system of equations to solve this problem, with the following variables:
- A: The number of hours Amir worked.
- B: The number of hours Beth worked.
- C: The number of hours Charlie worked.
We are given the following information:
- B = 2A
- C = A + 5
- A + B + C = 85
We can substitute the first two equations into the third equation to get:
A + (2A) + (A + 5) = 85
Combining like terms, we get:
4A + 5 = 85
Subtracting 5 from both sides, we get:
4A + 5 - 5 = 85 - 5
4A = 80
Dividing both sides by 4, we get:

A = 20
Now that we know A, we can find B and C using the equations B = 2A and C = A + 5:
B = 2A = 2 × 20 = 40
C = A + 5 = 20 + 5 = 25
We are also given that Amir's share of the tips was £25.40. Let T be the total amount of tips received.
The ratio of the tips received by Amir, Beth, and Charlie is:
Amir:Beth:Charlie = A:B:C = 20:40:25 also 4:8:5
We can use this ratio to set up a proportion to find T:

Multiplying both sides by
, we get


Therefore, the total amount of tips received this week was £107.95.