Answer:
a
Step-by-step explanation:
68.181 mph
300 feet/3 seconds = 100ft/sec
100ft x 60 sec. =6000ft/min
6,000 x 60= 360,000ft/hour
then convert to miles
X = velocity of plane
y = velocity of wind
x - y = 1680/5 = 336 mph .....(1) [ plane flying against the wind]
&
x + y = 1680/4 = 420 mph....(2) [ plane flying with the wind]
Adding (1) and (2) to eliminate y gives
2x = 756
x = 378 mph is the speed of the plane with no wind.
Answer: THe last one.
Step-by-step explanation:
This question is, in essence, basically asking which numbers are less than -3. Looking at the numbers, it is clearly the last set.