# Another problem I posted, but not getting it.

• Nov 21st 2009, 09:03 AM
Another problem I posted, but not getting it.
Bill can do a jobin 3.8 j, and john can do the same job in 5.4h. How will it take them to do the job together? ROUND your answer to the nearest quarter of an hour??
I know you add 1/3.8+1/5.4 = time on HOW long it will take to do together.

I have looked online to show how to add fractions with decimals, when you have to find the LCD to cancel them out.
That is what I don't know how to do.
Joanne
• Nov 21st 2009, 09:37 AM
e^(i*pi)
Quote:

Bill can do a jobin 3.8 j, and john can do the same job in 5.4h. How will it take them to do the job together? ROUND your answer to the nearest quarter of an hour??
I know you add 1/3.8+1/5.4 = time on HOW long it will take to do together.

I have looked online to show how to add fractions with decimals, when you have to find the LCD to cancel them out.
That is what I don't know how to do.
Joanne

Multiply by $\frac{10}{10}$ to clear the decimal

$\frac{10}{38} + \frac{10}{54}$

Spoiler:
The LCD of 38 and 54 is 1026
• Nov 21st 2009, 09:46 AM
HallsofIvy
Quote:

Bill can do a jobin 3.8 j, and john can do the same job in 5.4h. How will it take them to do the job together? ROUND your answer to the nearest quarter of an hour??
I know you add 1/3.8+1/5.4 = time on HOW long it will take to do together.

I have looked online to show how to add fractions with decimals, when you have to find the LCD to cancel them out.
That is what I don't know how to do.