Answer:
Speed of the southbound plane = 450 mph
Step-by-step explanation:
Let the speed of the northbound plane = x miles per hour
And the speed of the southbound plane = y mph
Since, northbound plane travels 70 mph faster than the southbound plane,
x = y + 70 -----(1)
The planes are 1940 miles apart in 2 hours.
From the formula,
Distance traveled = Speed × time
Distance traveled by northbound plane in 2 hours = 2x miles
Distance traveled by the southbound plane in 2 hours = 2y miles
2x + 2y = 1940
x + y = 970 -----(2)
By substituting the value of x in equation (2) from equation (1)
y + 70 + y = 970
2y = 970 - 70
y = 450 mph
from equation (2)
x + 450 = 970
x = 520 mph
