A school library needs four computer for every 7 students. If the school has 280 students, how many computers does it need?

2 Answers
Oct 26, 2016

The school needs #160# computers.

Explanation:

School needs #4# computers for #7# students.
#implies 7# students need #4# computers.

#implies 1# student need #4/7# computers.

#implies 280# students need #(280*4)/7# computers.

#implies 280# students need #(40*4)# computers.

#implies 280# students need #160# computers.

#implies# The school needs #160# computers.

Mar 2, 2017

#160 # computers

Explanation:

We can read from this that for every group of #7# students there should be 4 computer.

It will help to find out how many groups of #7# students there are in the school.

#280 div 7 = 40# groups

Each group should have 4 computers:

#40 xx 4 = 160# computers

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
We can also do this by direct proportion where we compare the number of students with the number of computers.

#("students"rarr)/("computers"rarr) " "7/4 = 280/x#

#7x = 280 xx 4#

#x = (280 xx4)/7#

#x = 160#