If there are 12 items adding up to 60%, we want to know how many items more it will take to equal 100% So set up this equation 12/x = .6 then solve for x. x=12/.6 x = 20 now that we know the total you can subtract 12 from 20 and get 8, that is the number of items left on the list.
Answer:
5
Step-by-step explanation:
The old photocopier can make x manuals in an hour. The new photocopier can make 4x. Combined, they made 5x manuals in an hour.
In one hour they can make 1/28 of the manuals.
1/(28*5)=1/140 is the rate.
The new photocopier can make all the manuals in 4/140 or 35 hours.
The old one can make them in 140 hours.
10 to 11 = 1 hr
11 to 12 = 1 hr
12 to 1 = 1 hr
total = 3 hours