Question

An airplane flew for 8 hours at an airspeed of x miles per hour (mph), and for 7 more hours
at 325 mph. If the average airspeed for the entire flight was 350 mph, which of the following
equations could be used to find x ?
A. x + 325 = 2(350)
B. x + 7(325) = 15(350)
C. 8 x – 7(325) = 350
D. 8 x + 7(325) = 2(350)
E 8 x + 7(325) = 15(350)

Answer 1

e is the asnwer

Answer 2

8hour at speed of x so its 8x and 7 more means add 7 so + 7
at 325mph so its 7(325)
entire flight gives ou clue that its equal to
entire flight is 15 hours 8+7 and its average speed is 350 so
15(350)

which gives you 8x + 7(325) = 15(350)

Answer 3

Doctors use the term maximum heart rate (MHR) when referring to the quantity found by
starting with 220 beats per minute and subtracting 1 beat per minute for each year of a
person’s age. Doctors recommend exercising 3 or 4 times each week for at least 20 minutes
with your heart rate increased from its resting heart rate (RHR) to its training heart rate
(THR), where THR = RHR + .65(MHR – RHR)
Which of the following is closest to the THR of a 43-year-old person whose RHR is 54 beats
per minute?
A. 197
B. 169
C. 162
D. 134
E. 80