Question

Suppose you can get a higher interest rate on your savings account if you maintain a balance of at least $1000 in your account. The balance in your account now is $1058. What is the greatest amount that you can withdraw and still get the higher interest rate?

Answer 1

We know that

• The balance is $1058.

,

• Also, the minimum balance is $1000.

When we talk about inequalities, "minimum" refers to more or equal than. That means the minimum balance is $1,000. In other words, the greatest amount you can withdraw is $58. This is represented with the following inequality

`0\leq w\leq58`

Notice that we need to use a double inequality, that is because we can't withdraw negative numbers, that's why we limit the range from zero to 58.