Question

Tom and Carl start 200 miles apart, running towards each other. Tom runs 5 miles per hour faster than Carl. If they meet after 10 hours, how fast are they running?

Answer 1

• Toms speed be a and Carl's speed be b

Now

• a=b+5
• 10(a+b)=200

From eq(2)

• a+b=20

From eq(1)

• a-b=5

Adding these recent two

• 2a=25
• a=12.5mph

Putting in eq(1)

• b=a-5
• b=12.5-5
• b=7.5mph

Answer 2

• 12.5 mph and 7.5 mph

Explanation:

• Tom's speed = x
• Carl's speed = y

We have:

• x = y + 5
• (x + y)*10 = 200

Substitute x and solve for y:

• (y + y + 5)*10 = 200
• 2y + 5 = 20
• 2y = 15
• y = 7.5

Find x:

• x = 7.5 + 5 = 12.5

Tom's speed is 12.5 mph

Carl's speed is 7.5 mph