If Bob, working alone, can paint a certain room in 3 hours,

[BTGmoderatorLU]

Source: Manhattan Prep

If bob, working alone, can paint a certain room in 3 hours, how long does it take Bob and Richard working together to paint the room?

1) Richard, working alone, can paint the room in 2 hours.
2) Richard paints at a constant rate that is 50% greater than the rate at which Bob paints.

The OA is D

[Jay@ManhattanReview]

Source: Manhattan Prep

If bob, working alone, can paint a certain room in 3 hours, how long does it take Bob and Richard working together to paint the room?

1) Richard, working alone, can paint the room in 2 hours.
2) Richard paints at a constant rate that is 50% greater than the rate at which Bob paints.

The OA is D

We know Bob's rate; if we know Richard's rate, we can find out their combined rate.

Statement 1 provides Richard's rate. So, Statement 1 alone is sufficient.

From Statement 2, we know Richard's rate is 50% faster than Bob's. Thus, Richard would take 3/(100 + 50)% days = (3/150)*100 = 2 days.

This is the same information that Statement 1 gives. So, Statement 2 alone is also sufficient.

The correct answer: D

Hope this helps!

-Jay
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