A blueprint for a house shows the height of the house to be 3 1/2 inches. The actual house is 21 1/3 feet tall. What is the unit rate in feet per inch?
A. 7/128 foot per inch
B. 6 2/21 feet per inch
C. 21/128 foot per inch
D. 2 2/7 feet per inch

Question

A blueprint for a house shows the height of the house to be 3 1/2 inches. The actual house is 21 1/3 feet tall.  What is the unit rate in feet per inch?
A. 7/128 foot per inch
B. 6 2/21 feet per inch
C. 21/128 foot per inch
D. 2 2/7 feet per inch

jim_thompson5910 · Answer

they want you to divide `21 1/3` by `3 1/2`

jim_thompson5910 · Answer

first you'll need to convert the mixed numbers to improper fractions

example:

3 1/2 = 3+1/2
3 1/2 = 3*(2/2)+1/2
3 1/2 = 6/2+1/2
3 1/2 = 7/2

shadowcain · Answer

Don't you have to convert feet into inches first?

jim_thompson5910 · Answer

no, just divide the two numbers without converting

notice how the rate is "feet per inch", so you'll have "feet" over "inches"

shadowcain · Answer

Thanks

jim_thompson5910 · Answer

you're welcome