Please help me with these 2 word problems

Question

Mattie Evans drove 300 miles in the same amount of time that it took a turbopropeller plane to travel 1100 miles. The speed of the plane was 160 mph faster than the speed of the car. Find the speed of the plane.

 

One more question I need help with please.

 

The speed of a river current is 5mph. If a boat travels 30 miles downstream in the same time that it takes to travel 20 miles upstream, find the speed of the boat in still water.

 

Answer 1

First, find the difference between the plane's total miles and the car's total miles:  1100 - 300 = 800

 

Second, divide the difference of total miles (800) by the plane's faster mph of the car (160) to equal the total of travel hours:

800/160 = 5 travel hours

 

Third, divide the plane's total miles (1100) by the travel hours (5) to equal the plane's speed (or miles per hour):

1100/5 = 220 mph for the plane.

 

2nd Problem:

 

River Current = -5mph or +5mph

Speed of the boat = x

 

First, solve the variable for Downstream:

Downstream = Increase of speed = (x + 5mph = 30mph)

 

Second, subtract 5mph from each side of the equal sign:

x + (5mph - 5mph) = (30mph - 5mph)

 

Third, condense the equation:

x + 0 = 25 mph  or 

x = 25 mph

 

Speed of the boat = 25mph

 

or

 

First, solve the variable for upstream:

Upstream = Decrease of speed = (x + -5mp = 20mp)

 

Second, add 5mph to both sides of the equal sign:

x + (-5mp + 5mph) = (20mph + 5mph)

 

Third, condense the equation:

x + 0 = 25mph  or

x = 25mph

 

Speed of the boat = 25mph