word problem help 4

Question

Two boats started to move towards each other from two docks, located 30 miles apart. One boat moved at a speed of 2.5 miles per hour, the other moved twice as fast. How soon will the boats meet?

Answer 1

Here's what we know:

(2.5 ^mi/_hr + 5 ^mi/_hr)t = 30 mi (two boats moving at their collective speeds will cover 30 miles eventually)

 

Simplify:

7.5 ^mi/_hr t = 30 mi

Divide both sides by 7.5 ^mi/_hr

t = 30 mi / 7.5 ^mi/_hr

Cancel out miles:

t = ³⁰/_7.5 hr

 

Complete the division, and you'll have your answer.