A store sells shirts at three prices only: $25, $30, and $35. How many different combinations are possible for the store to sell 20 shirts for a total of $600?

  11

Step-by-step explanation:

The average price of the 20 shirts is 600/20 = $30 each. So, we know that we can sell 20 shirts for $30 each to reach the goal.

For each $25 shirt we sell, we must also sell a $35 shirt to make the average price of the sale be $30 per shirt. That is any or all of the 10 pairs of $30 shirts can be replaced by a ($25, $35) pair. So, there are 10 additional ways to reach the goal.

The total number of possible combinations of shirt sales is 1 +10 = 11.

3< x< 5

step-by-step explanation:

|x - 4| < 1

there are two solutions, one positive and one negative.   remember to flip the inequality when taking the negative solution

x-4 < 1       x-4 > -1

add 4 to each side

x-4+4 < 1+4       x-4+4 > -1+4

x< 5                 x> 3

3< x< 5