For each trip, a taxi company charges a fixed fee of $2.00 plus $0.75 for each 1/2 mile or fraction of 1/2 miles. If, for every number x, [ x ] is defined to be the least integer greater than or equal to x, then which of the following represents the company's charge, in dollars, for a trip that is r miles long?A. 2.00 + [ \(\frac{0.75r}{2}\) ]B. 2.00 + 0.75[ \(\frac{r}{2}\) ]C. 2.00 + 0.75[ r ]D. 2.00 + [1.5r ]E. 2.00 + 0.75 [ 2r]Hi, people, let's get into this!
First, think of a random distance (e.g. 5.4 miles) and manually figure out the cost based on the prompt: $10.25
Then, see which of the options would spit out a similar value, keeping in mind the [x] condition. Remember, we’re looking for an equation that will give us more than $10 so (A), (B), and (C) are clearly out therefore.
When we look at (D) and (E),
(D) spits out 2 + [1.5 x 5.4] or 2 + [8.1]: $11
(E) is the answer therefore and we can also check it: $2 + $0.75 [2 (5.4)] = $2 + 0.75 (11) = $10.25
Note: Being a little extra careful and testing two distance values can be prudent.