# distance

posted by on .

An executive drove from home at an average rate of speed of 30 mph to an airport where a helicopter was waiting. The executive boarded the helicopter and flew to the corporate offices at an average speed of 60 mph. The entire distance was 150 miles. The entire trip took 3 hours. What is the distance from the airport to the corporate offices?

Distance = rate x time

let the time by helicopter be x hrs, then the time he drove would be 3-x hrs

Distance in helicopter = 60x
distance driven = 30(3-x)

so 60x + 30(3-x) = 150

solve for x, then sub into 60x

tell me what you got, I got 120

An instructor asked his/her class to evaluate the expression 1/2x for x = 5. Some students gave 0.1 for an answer while others gave 2.5. Which answer is correct?

Note: I cam eup with 0.15?

The way you wrote it as 1/2x, one has to follow the order of operation and it would be 1÷2*x which is then 1÷2*5 = 2.5

to obtain .1 you would have written it as
1/(2x)

I don't see how you could obtain .15 as an answer.