John bikes at a speed of 10 miles per hour. His friend Brian is slower, his biking speed is only 8 miles per hour.

Today the boys went for a 20 miles trip, each boy was biking at his usual speed. How long did John wait for Brian at the finish line?

PL HELP QIUCK

John waited for Brain at the finish line for a half-hour. (or 30 minutes)

Step-by-step explanation:

The rule of the distance is D = s × t, where

Let us use this rule to solve the question

∵ John's speed = 10 miles/hour

∵ Brian's speed = 8 miles/hour

→ Slower speed takes more time

∵ The distance of the trip is 20 miles

∴ D = 20 miles

→ Find the time of each one, using the rule above

∵ D = s × t

→ Find John's time

∴ 20 = 10 × t

∴ 20 = 10t

→ Divide both sides by 10

∴ 2 = t

∴ John's time = 2 hours

→ Find Brian's time

∴ 20 = 8 × t

∴ 20 = 8t

→ Divide both sides by 8

∴ 2.5 = t

∴ Brain's time = 2.5 hours

→ Subtract their times to find for how long John waited

∵ 2.5 h - 2 h = 0.5 h

∴ The difference between their times is 0.5 hour

∴ John waited for Brain at the finish line for a half-hour (or 30 minutes)

x=half

step-by-step explanation: