Question

Polly stacked the tins from five boxes of cat food onto an empty shelf in a supermarket. There were 15 tins of cat food in each box. At the end of the week there were 20 tins left on the shelf. The rest of the tins had been sold. Write the number of boxes of cat food that had been sold, as: (a) A mixed number (b) An improper fraction

Answer 1

(a)
`3(2)/(3)` boxes of cat food had been sold.

(b)
`(11)/(3)` boxes of cat food had been sold.

Explanation:

From the question,

Polly stacked the tins from five boxes of cat food onto an empty shelf and there were 15 tins of cat food in each box. That is,

5 × 15 tins of cat food were stacked onto the empty shelf.

5 × 15 = 75

Hence, 75 tins of cat food were stacked onto the empty shelf.

Also, from the question,

At the end of the week there were 20 tins left on the shelf and the rest of the tins had been sold, that is

75 - 20 tins had been sold

75 - 20 = 55

Hence, 55 tins of cat food had been sold.

To determine the number of boxes of cat food that had been sold,

Since there are 15 tins of cat food per box, then

we will divide 55 tins of cat food that had been sold by 15 tins of cat food per box

55 ÷ 15 =
`(55)/(15)`

Hence,
`(55)/(15)` boxes of cat food had been sold

(a) As a mixed number

`(55)/(15) = 3(2)/(3)`

Hence,
`3(2)/(3)` boxes of cat food had been sold.

(b) As an improper fraction

`(55)/(15) = (11)/(3)`

Hence,
`(11)/(3)` boxes of cat food had been sold.