# Help with percentage problem please!

• February 3rd 2010, 09:44 AM
punky
I need a little help with the following problem.

Student A is attending a study course for 12 weeks in total.
He has just finished 10 of the 12 weeks.
His attendance after 10 weeks is at 70%.
If he goes to all his classes for the remaining 2 weeks, what will his attendance be at the end of the course?

I'm unsure how to calculate this.
Thanks!
Punky.
• February 3rd 2010, 10:50 AM
Quote:

Originally Posted by punky
I need a little help with the following problem.

Student A is attending a study course for 12 weeks in total.
He has just finished 10 of the 12 weeks.
His attendance after 10 weeks is at 70%.
If he goes to all his classes for the remaining 2 weeks, what will his attendance be at the end of the course?

I'm unsure how to calculate this.
Thanks!
Punky.

Hi punky,

70% of 10 weeks is 7 weeks.

$\frac{70}{100}10=\frac{10}{100}70=\frac{70}{10}=7$

If he attends all of the remaining 2 weeks, then he will have attended 7+2 = 9 out of 10+2=12 weeks.

9 out of 12 is $\frac{9}{12}100\%=\frac{900}{12}\%=75\%$

To change a fraction to a percentage, multiply by 100.
• February 3rd 2010, 10:54 AM
earboth
Quote:

Originally Posted by punky
I need a little help with the following problem.

Student A is attending a study course for 12 weeks in total.
He has just finished 10 of the 12 weeks.
His attendance after 10 weeks is at 70%.
If he goes to all his classes for the remaining 2 weeks, what will his attendance be at the end of the course?

I'm unsure how to calculate this.
Thanks!
Punky.

Let us assume that the course has x hours per week. Then A should have attended 10x hours in 10 weeks. Actually he has only taken part at 70% of 10 x h, that means he has taken part at 7x hours.

He now attends the remaining 2x hours and at the end of the course he has attended 7x + 2x = 9x hours of 12x possible hours. That's a percentage of 75%.