Question

two apples and 1 banana contain a total of 285 calories. an apple has 15 less calories than a banana. how many calories does each fruit contain

Answer 1

Each apples contain 90 calories while each bananas contain 105 calories.

Explanation:

Let x be the calories of apple and y be the calories of banana:

`\displaystyle{2x + y = 285}`

Since an apple has 15 less calories than a banana:

`\displaystyle{x = y-15}`

Solve the simultaenous equations; substitute x = y - 15 in 2x + y = 285:

`\displaystyle{2\left(y-15\right) + y = 285}\\\\\displaystyle{2y-30+y=285}\\\\\displaystyle{3y=285+30}\\\\\displaystyle{3y=315}\\\\\displaystyle{y=105}`

We know the calories of banana now but we have not known the calories of apple yet. Therefore, substitute y = 105 into x = y - 15:

`\displaystyle{x=105-15}\\\\\displaystyle{x=90}`

Hence, the calories of each apples contain 90 calories and the calories of each bananas contains 105 calories.