Question

Bertrand collects movie posters. The number of movie poster in his collection each month as he buys and sells posters.The table shows how many poster he bought or sold in the given month.

January February March April
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sold 20 bought 12 brought 22 sold 28

a) Which month have changes that can be represented by positive number? Which month have changes that can be represented by negative number?

THANKS FOR HELPING 'ω'

Answer 1

All of the months can be represented by both. If he sells 20 posters that is a negative in terms of the posters but he received money for them so his money goes up while the amount of the posters goes down. Same for if he buys. The number of posters goes up but his cash goes down. 

Answer 2

January February March April

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sold 20 bought 12 bought 22 sold 28

A: February and March have changes that can be represented by positive number as items are bought here.

January and April have changes that can be represented by negative number as items are sold here.