MI3 wrote:Q: Joe, Bob and Dan worked in the ratio of 1:2:4 hours, respectively. How many hours did Bob work?
(1) Together, Joe, Bob and Dan worked a total of 49 hours.
(2) Dan worked 21 hours more than Joe.

IMO - A, am I correct?

Answer should be D, as stat. (2) also gives you a foothold in reality - it tells you that the difference between Dan and Joe (4-1=3 ratio units) corresponds with a difference of 21 hours in Reality. So the multiplier between ratio and reality is *7, which applies across the board:
A ratio of 1:2:4 expanded times 7 will yield a real number of hours of 7:14:28, and only this ratio will satisfy the condition for the difference of 21 hours. From this, we can infer tha Bob worked for 14 hours.

IMO D.
As both the statements are alone sufficient.

Both statements are sufficient...
because you can always compute the Part if the whole is given in the ratio
and similarly if any of two of the ratio or there difference is given.
So 1 & 2 are sufficient.

IMO also it is D