# If it took Jane 3/4 hour by long will it take to paint a wall that was 12 ft by 12 ft, how long will it take to paint another wall that is 15 ft by 16 ft?

##### 1 Answer

#### Explanation:

The idea here is that you need to figure out how much time is needed to paint

#"12 ft" xx "12 ft" = "144 ft"^2# This is the case because the area of a rectangle--or a square, like you have in this case--is calculated by multiplying the length and the width of the rectangle.

So, you know that Jane needs

#1 color(red)(cancel(color(black)("ft"^2))) * (3/4 quad "h")/(144color(red)(cancel(color(black)("ft"^2)))) = 1/192 quad "h"#

Now, the area of the second wall is equal to

#"16 ft" xx "15 ft" = "240 ft"^2#

This means that Jane will paint this wall in

#240 color(red)(cancel(color(black)("ft"^2))) * (1/192 quad "h")/(1color(red)(cancel(color(black)("ft"^2)))) = 5/4 quad "h" = "1.25 h"#

You can thus say that Jane will need **hours**, or **hour** and **minutes**--remember that