Practice Problems - Basic Math, Linear equations etc

I need help with the attached questions. You will have to open up the attachment to see the questions with proper formatting.

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18. 13/18 + 11/18

39. 18/23 - 13/23 - 3/23

44. Number problem. One task took 7 minutes (min), a second task took 12 min, and a third task took 21 min. How long did the three tasks take, as a fraction of an hour?

50. Geometry. Find the perimeters of the following triangles

3/8cm 3/8cm 3/8cm

22. Find the least common multiple (LCM) for each of the following group of numbers. Use which ever method you wish

12, 20, and 35

Perform the indicated operations

26. 1 1/15 + 3 3/10 - 2 4/5

30. Statistics. Robin ran 5 1/3 miles on Sunday, 2 1/4 miles on Tuesday, and 3 1/2 miles on Friday. How far did she run during the week?

48. Business and finance. 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?

14. Business and finance. Julio works as a quality control expert in a beverage factory. The assembly line that he monitors produces about 20,000 bottles in a 24-hour 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?

16. Business and finance. 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)?

24. 7 11/12 divided by 6 1/10

Benjamin and Olivia are putting a new floor in their kitchen. To get the floor up to the desired height, they need to add 1 1/8ft of sub floor. They can do this in one of two ways. They can put 1/2in. sheet on top of 5/8in. board (note that the total would be 9/8ft or 1 1/8ft). They could also put 3/8in. board on top of 3/4in. sheet. The table below gives the price for each sheet of plywood from a Home Depot store on 1/15/04.

Thickness cost for a 4ft x 8ft sheet.

1/8in. $9.15
1/4in. $13.05
3/8in. $14.99
1/2in. $17.88
5/8in. $19.13
3/4in. $21.36
7/8in. $25.23
1 in. $28.49

1. What is the combined price for a 1/2in. sheet and a 5/8in. sheet?

2. What is the combined price for a 3/8in. sheet and a 3/4in. sheet?

3. What other combination of sheets of plywood yields the needed 1 1/8in. thickness?

4. Of the four combinations, which is most economical?

5. The kitchen is to be 12ft X 12ft. Find the total cost of the plywood you have suggested in question 4.