SOLUTION: Can someone help me here on this problem? Jon spent 1/3 of his study time doing math homework and 2/7 preparing for a history exam. What fraction of his study time remains?

Algebra ->  Numeric Fractions Calculators, Lesson and Practice -> SOLUTION: Can someone help me here on this problem? Jon spent 1/3 of his study time doing math homework and 2/7 preparing for a history exam. What fraction of his study time remains?      Log On


   

Question 44266: Can someone help me here on this problem?
Jon spent 1/3 of his study time doing math homework and 2/7 preparing for a history exam.
What fraction of his study time remains?
Thanks, Lyn
Answer by adamchapman(301) About Me  (Show Source):
You can put this solution on YOUR website!
All of his time (as a decimal) is 100%=1.00
As a fraction this is 1/1=1.
To work out the time left, subtract the time spent from one:
timeleft=1-1%2F3-2%2F7
this can be done fairly easily with a calculator, but if you don't have one handy you need to get rid of the denominators.
Let
t = time left
t=1-1%2F3-2%2F7
multiply by the denominators to eliminate the fractions:
3t=3-1-6%2F7
21t=21-7-6
21t=8
Now t=8%2F21
I hope this helps.
P.S. I am trying to start up my own homework help website. I would be extremely grateful if you would e-mail me some feedback on the help you received to adam.chapman@student.manchester.ac.uk