Word problem in algebra?

Question

A boat can travel at 10 mph in still water. It travels 75 miles downstream with the current in the same time it travels 25 miles upstream. What is the speed of the current?

5 mph

6 mph

7 mph

12 mph

5: This airplane would travel 350 mph in still air. However, airplanes always travel on air currents. With the air current, the airplane travels 1120 miles in the same time that it travels 980.1 miles against the air current. Find the speed of the air current.

17.8 mph

23.3 mph

26 mph

27.6 mph

Answer 1

A boat can travel at 10 mph in still water. It travels 75 miles downstream with the current in the same time it travels 25 miles upstream. What is the speed of the current?

Time = distance / velocity.

75 / ( 10 + C ) = 25 / ( 10 - C )

C = 5 mph.

This airplane would travel 350 mph in still air. However, airplanes always travel on air currents. With the air current, the airplane travels 1120 miles in the same time that it travels 980.1 miles against the air current. Find the speed of the air current.

1120 / ( 350 + W ) = 980.1 / ( 350 - W )

W = 23.3 mph.

Answer 2

1) (10 +x )/ 75 = (10-x) / 25

10+x /3 = 10-x

10 +x = 30 -3x

4x = 20

x= 5mph