A local restaurant is hosing a dance-a-thon for charity. Each couple must dance a minimum of three hours before earning any money for the charity. After the first three hours, couples earn `$50` per half-hour of continous dancing. Which expression represents the total amount earned by a couple who dance h hours, assuming they dance at least three hours ?

Options

A. 25 h
B. 100 h
C. `50(h-3)`
D. `100h -300`

Answer

D

Explanation

Use the information in the question to write your own expression, then look for the answer choice that matches. Simplify your expression only if you don't find a match. IF a couple earns `%50` per half-hour that they dance, then they earn `50xx2=$100` per hour. Multiply this amount by the number of hours (not including the first 3 hours). This can be expressed as `100(h-3).` This is not one of the answer choices, so simplify by distributing the 100 to get 100h- 300, which is (D).
If you're struggline with the algebra, try Picking Numbers. Pick a number of hours a couple might dance, like 5. They don't earn anything for the first 3 hours, but they earn `$50` per half-hour for the last 2 hours, whic is 50 times 4 half-hours, or `$200` when `h=5` hours: `100(5)-300=500-300=200.` If you use Picking Numbers, remember that it is possible that the number you choose satisfies ore than one answer choice, so plug it in to the other three choices. In this case, `h=5` does not give a value of 200 in any other equation, which confirms that(D) is correct.