Question

ASB is selling In-N-Out as a fundraiser. Fries cost $2 and shakes cost $3. Students can only buy one item each. ASB wants to know which sells better but they lose track of what they sold. They know 105 students bought either fries or a shake. They count their money and it's $245. How many fries (x) and shakes (y) did they sell?

Answer 1

The number of fries and shakes sold are 70 and 35 respectively.

Explanation:

The number of fries sold can be denoted by x.

The number of shakes sold can be denoted by y.

The equation representing the total number of items sold is:

x + y = 105...(i)

The cost fries is, $2.

The cost of shakes is, $3.

The equation representing the total money earned is:

2x + 3y = 245...(ii)

Solve equations (i) and (ii) simultaneously as follows:

Multiply equation (i) by 3 and subtract:

3x + 3y = 315

2x + 3y = 245

(-) (-) (-)

___________

x = 70

Compute the value of y as follows:

x + y = 105

70 + y = 105

y = 105 - 70

y = 35

Thus, the number of fries and shakes sold are 70 and 35 respectively.