Question

A grandmother wants to spend at least $40 but no more than $60 on school clothes for her grandson. T-shirts sell for $10 and pants sell for $20. How many T-shirts and pants could she buy?

Answer 1

Using all of the $60

`color(white)(.)"2 pants and 2 T-shirts"`

`color(white)(.)"1 pants and 4 T-shirts"`

Explanation:

Let me introduce you to a couple of new terms. These tend to be used in the contexts of ranges of something.

In this case we have a maximum value: Term `->" Upper bound"`
In this case we have a minimum value: Term `->" Lower bound"`

The difference between upper and lower bound is $20. This is the price of 1 pair of pants.

.......................................................................................
`color(brown)("The maximum count of pants and uses upper bound")`

3 pants `->3xx$20=$60` which uses up all the money

2 pants `->2xx$20=$40` which is the least reduction of pants
`color(white)("ddddddddddddddddd")` and leaves $20 for T-shirts `->2`T-shirts.

.......................................................................................
`color(brown)("The maximum count of T-shirts and uses upper bound")`

1 pants `->1xx$20=$20` which is the most reduction of pants
`color(white)("ddddddddddddddddd")`and leaves $40 for T-shirts `->4`T-shirts

So we have

2 pants and 2 T_shirts
1 pants and 4 T_shirts