If Amanda walks at an average speed of 2.72 miles per hour, how long will it take her to walk 6.8 miles?

1 Answer
Aug 2, 2016

It'll take Amanda 2.5 hours to walk 6.8 miles

Explanation:

Let's set up a proportion that compares miles to minutes based on the given ratio and the ratio that you want to find:

#(2.72 "miles")/(1 "hour") = (6.8 "miles")/(x "hours")#

The left side shows the proportion of miles to hours that you've given me, and the right side shows the number of miles that we know over the unknown time expressed in hours.

#color(blue)("You can obtain the answer using cross multiplication:"#

www.mathsisfun.com

Multiply 1 and 6.8 together:

#1"hour" xx 6.8"miles"# = #6.8#

Multiply #2.72 and x# together:

#2.72xx x# = #2.72x#

Set #2.72x and 6.8# equal to each other. Then divide by 2.72 on both sides of the equation to get #x# by itself:

#(2.72x)/cancel2.72 = 6.8/2.72#

#x = 2.5 "hours"#