SOLUTION: Hi, I would like to say thank you for your help in advanced! So my question is : If a carpenter can roof a house in 10 days and another can do the same roof in 14 days, how m

Algebra ->  Rate-of-work-word-problems -> SOLUTION: Hi, I would like to say thank you for your help in advanced! So my question is : If a carpenter can roof a house in 10 days and another can do the same roof in 14 days, how m      Log On


   

Question 993390: Hi,
I would like to say thank you for your help in advanced!
So my question is : If a carpenter can roof a house in 10 days and another can do the same roof in 14 days, how many days will it take if they work together?
I would like you to tell me where I went wrong.
Here is the equation that I came up with.
1/10 + 1/14 = 1/t
I know I am missing something because I keep having issues with these types of problems.
Thanks,
Anthony



Found 3 solutions by ikleyn, macston, MathTherapy:
Answer by ikleyn(52781) About Me  (Show Source):
You can put this solution on YOUR website!
.
1%2F10 + 1%2F14 = 7%2F70 + 5%2F70 = 12%2F70 = 6%2F35.

Hence,  t = 35%2F6 = 55%2F6  days.

Many of typical  "joint work"  problems are considered and solved in the lesson  Using fractions to solve word problems on joint work  in this site.

Look in it,  and you will improve your skills!

It is free of charge and without registration.


Answer by macston(5194) About Me  (Show Source):
You can put this solution on YOUR website!
.
1%2F10%2B1%2F14=7%2F70%2B5%2F70=12/70
Together they roof 12/70 of a house per day
.
12/70=1/t
70/12 days = t
5 10/12 days=5 5/6 days=t
.
ANSWER: Together they can roof the house in 5 and 5/6 days.
Most likely error is combining and dividing fractions.

Answer by MathTherapy(10552) About Me  (Show Source):
You can put this solution on YOUR website!

Hi,
I would like to say thank you for your help in advanced!
So my question is : If a carpenter can roof a house in 10 days and another can do the same roof in 14 days, how many days will it take if they work together?
I would like you to tell me where I went wrong.
Here is the equation that I came up with.
1/10 + 1/14 = 1/t
I know I am missing something because I keep having issues with these types of problems.
Thanks,
Anthony 
That equation is correct!! Good job!

This is what you have: 1%2F10+%2B+1%2F14+=+1%2Ft

7t + 5t = 70 -------- Multiplying by CD, 70t

12t = 70

t, or time = 70%2F12, or highlight_green%285%265%2F6%29 days