Harry bought 2 mints and 5 apples for $2.36
Craig bought 4 mints and 3 apples for $1.78
firstly, let x represent the number of mints and let y represent the number of apples
For Harry
2 * x + 5 * y = 2.36
2x + 5y = 2.36 -------- equation 1
For Craig
4 * x + 3 * y = 1.78
4x + 3y = 1.78 --------- equation 2
2x + 5y = 2.36
4x + 3y = 1.78
These two equations can be solve simultaneously and we will be using the elimination method.
Let us eliminate x first
To eliminate x, we will mulitply 2 by equation 1 and 1by equation 2
2x * 2 + 5y * 2 = 2.36 x 2
4x * 1 + 3y * 1 = 1.78 x 1
4x + 10y = 4.72 ----- equation 3
4x + 3y = 1.78 -------- equation 4
substract equation 4 from equation 3
4x - 4x + 10y - 3y = 4.72 - 1.78
0 + 7y = 2.94
7y = 2.94
divide both sides by 7
7y/7 = 2.94/7
y = 0.42
To find x, substitute y = 0.42 in equation 1
2x + 5y = 2.36
2x + 5(0.42) = 2.36
2x + 2.1 = 2.36
make 2x the subject of the formula
2x = 2.36 - 2.1
2x = 0.26
divide both sides by 2
2x/2 = 0.26/2
x = 0.13
since x = mint and y = apples
The cost for a mint is $0.13 and the cost for an apple is $0.42