A plane flies from Portland, ...(math help)?

Question

Question 18:
A plane flies from Portland, ME to El Paso, TX with an average speed of 303 mph. A car drives the same distance and leaves at the same time, averaging a speed of 50 mph. The plane arrives in El Paso 35.42 hours before the car. How far is it from Portland to El Paso? Use a chart to help you organize the information.





miles
Question 19:
The Party Bank pays four percent simple interest per year on deposits. Connor was paid $1,104 of interest over a four year period. How much did he originally deposit?





$
Question 20:
Alexis left a location at 8 a.m. The channel three news sent a helicopter from the same location eight hours later to catch up with Alexis. The helicopter's average rate of speed is one hundred fifty mph. If Alexis traveled at 53 mph, how far did she drive?





Enter a decimal rounded to the hundredths place.
miles

Answer 1

18.
The distances are equal, so x = vt is the same
303t = (t+35.42)*50
6.06t = t + 35.42
t = 35.42/5.06
t = 7.00, therefore
x = 7 * 303 = 2121 and
x = (7+35.42)*50 = 2121 (check)

This is the correct distance between Portland, ME and El Paso, TX.

19.
P(1.04)^4 = 1104
P = 1104/1.17
P = 943.70

20.
Again, the distances are equal, so x = vt is the same
150t = (t+8)*53
2.83t = t + 8
t = 8/1.83
t = 4.37, therefore
x = 4.37 * 150 = 655.74 and
x = (4.37+8)*53 = 655.61 (check)

Answer 2

#18
rate * time = distance
PLANE:
rate = 303
time = x
distance = 303x

CAR:
rate = 50
time = x + 35.42
distance = 50(x+35.42)

The distances are the same (in theory), so set those equal:

303x = 50(x+35.42)
303x = 50x + 1771
253x = 1771
x = 7

So the plane too 7 hours to fly to Texas. The distance is 303x = 303(7) = 2121 miles

You should be able to solve #20 in the same way.

(Edit: had wrong speed for car. fixed now.)