Bunuel
If a group of five Democrats take 3 hours to write a proposal, how long will it take a group of 4 Republicans to write the same proposal?
(1) A Republican writes at 2/3 the rate of a Democrat
(2) 5 Democrats and 4 Republicans writing together will take \(1 \frac{9}{10}\) hours to finish the proposal
What we need is the work rate per hour of a Republican to write a proposal. Note this is a DS question; so, we needn't actually solve it. As long as we can frame a linear equation, we should be good.
Group of 5 democrats takes 3 hours to write a proposal.
So, the work rate of a Democrat: 1/D = 1/3*1/5 = 1/15. (It takes one democrat 15 hours to complete the proposal.)
Statement 1:
R = 2/3 rate of a Democrat -> 2/3 * 1/15 = 2/45 (It takes one Republican 22.5 hours to complete the proposal). We can hence find how much time it will take 4 Republicans.
Sufficient.Statement 2:
5 Democrats + 4 Republicans take 1 9/10 hours to complete the proposal/
We know the work rate of a democrat. We have the combined time on the other side. So, we can find the work rate of 4 republicans.
Sufficient.Hence:
DCheers