Question

URGENT AND SIMPLE question pls:))) You dont have to do all of it, if you could just give me the equation for this problem, that would be great. Ann can build a model car in 3 hours, while Sam can build the same model in 6 hours. How many hours would it take them to build it together? Set up a rational equation and solve for x.

Answer 1

If Ann can build the model in 3 hours, then in 1 hour she gets 1/3 of it done. Likewise, if Sam can build the model in 6 hours, then in 1 hour he gets 1/6 of it done. We are looking to find how long it takes when they combine their efforts, so we will add the two together and set it equal to 1/x, x being the number of hours it takes for both of them to get the whole job done. The equation then looks like this: $\frac{1}{3}+\frac{1}{6}=\frac{1}{x}$. You will have to find the common denominator to add those fractions, and once you do, cross multiply to solve for x.