Answer:
Correct answer: Vsub = 5 mph
Step-by-step explanation:
Given:
t₁ = 2 h
Va = 25 mph
t₂ = 9 h
d = 280 mile
distance traveled by aircraft carrier for time t₂ = 9 h
d₃ = Va · t₂ = 25 · 9 = 225 miles
the total distance traveled by the submarine
d₁ + d₂ = 280 - 225 = 55 miles
d₁ + d₂ = Vsub · t₁ + Vsub · t₂ = Vsub · ( t₁ + t₂ ) = 55
Vsub · ( t₁ + t₂ ) = 55 ⇒ Vsub = 55 / 2 + 9 = 55 / 11 = 5 mph
Vsub = 5 mph
God is with you!!!