math
posted by Tonya on .
I need help bad.
Fractions
1)1/3 + 5/12 + 4/5 =
2)13/15  11/20 =
3)1 1/15 + 3 3/10  2 4/5 =
4)Robin ran 5 1/3 mi on Sunday, 2 1/4mi on Tues, and 3 1/2mi on Fri. How far did she run during the week?
5)The interest rate on an auto loan in May was 12 3/8%. By September the rate was up to 14 1/4%. How many percentage points did the interest rate increase over the period?
6)Julio works as a quality control expert in a beverage factory. The assembly line that he monitors produces about 20,000 bottles in a 24hour period. julio samples about 120 bottles an hour and rejects the line if he finds more than 1/50 of the sample to be defective. About how many defective bottles should Julio allow before rejecting the entire line?
7)Lunch meat sells for about $3 per pound. You use about 1/2 pound per day for sandwiches. How much should you budget for lunch meat over the next month (about 20 workdays)?
8)17 11/12 / 6 1/10 =

For the first three problems, you need to change these fractions so they have a common denominator. Then add or subtract the numerators.
Example:
1/3 + 5/12 + 4/5 =
The number that's divisible by 3, 12, and 5 is 60.
1/3 = 20/60
5/12 = 25/60
4/5 = 48/60
20/60 + 25/60 + 48/60 = ?
Please attempt the other problems and post your answers. We'll be happy to check them for you. 
These are exercises in converting to a common denominator, and then adding or subtracting fractions. Here is how to do the first one.
1) The common denominator is 3x4x5 = 60
1/3 + 5/12 + 4/5 = (20+25+48)/60 = 93/60
= 1 33/60 = 1 11/20 = 1.55
Now you try the others. There are many math teachers here willing to help student who make an effort. Someone will be glad to critique your work. 
9 1/5  7 6/25 = 46/5  181/25 =
230  181/25 = 49/25 = 1 24/25
Now estimate to see if the answer is reasonable by rounding each mixed number to the nearest integer then subtracting.