Question 1184129

Determine number of acres in a field if the length is to the width as 7 is to 3.  A person is walking at 4 mph for an hr. and 15 min. around the field.

Not sure how to solve.
<pre>Let multiplicative factor for length and width be x
Then length = 7x, and width = 3x
Perimeter of field: 2(7x + 3x) = 2(10x) = 20x
Walking at 4 mph for 1 hour and 15 min, or for {{{matrix(1,5, 1&1/4, hours, "=", 5/4, hours)}}}, we get: {{{matrix(4,3, 20x, "=", 4(5/4), 20x, "=", 5, x, "=", 5/20, x, "=", 1/4))}}}
With x being {{{1/4}}}, length = {{{matrix(1,3, 7(1/4), "=", 7/4)}}}, and width = {{{matrix(1,3, 3(1/4), "=", 3/4)}}}
Since acreage denotes AREA, we get area as: {{{highlight_green(matrix(1,6, (7/4) * (3/4), "=", 21/16, "=", 1&5/16, units^2))}}}