Can be formulated as a series of simultaneous equations - I.e. let x = # 50ps and let y = # 10ps, then the solution satisfies the equations:
5x + y = 85 and;
x + y = 10
So, using substitustion,
5x + 25 - x = 85
4x = 60
x = 15
y = 10
The answer is B)
I think the answer is (d). I agree with your method of using simultaneous equations to solve it but I came up with these two
50x + 10y = 850 (Based on x being the number of 50 p’s and y being the number of 10 p’s)
x + y = 25 (As we know in total there are 25 coins)
Solving these gives us: x=15 and y = 10
If the machine then returns 5 ten pence coins, this then leaves y=5 in the machine.
So our ratio of 50 pence coins to 10 pence coins in the machine at the end is 15:5, this simplifies to 3:1.
I think MathsFan may be right
Perhaps we can achieve consensus? #Collaboration
Spot on - the answer is d) and I didn’t fully read the question!