At a certain company, 64.5% of the employees have engineering degrees.
To express the percentage as a decimal we need to remove the % symbol.
To remove % symbol we always divide by 100
When we divide by 100 we move the decimal point two places to the left.

The decimal vale of 64.5% is 0.645
To find all of the feet of pipe that Brad has, you add both of the lengths of the pipes together. So 2 5/12+3 7/12. Add the numbers together first, 5. Then add the fractions, 5/12+7/12=1. So add 5 and 1 and you get 6 feet of pipe. Hope this helps.
-5/11 is what I got with a fraction calculator.