Concept: The question tests on the basics of Rates(Speed and Time)
Given that Nick + Greg + Jim = 54
To find how much Jim has
Statement 1: Jim has twice as much money as Greg and Nick has six times as much money as Greg has.
Let the amount that Greg has = x. Then Nick has 6x and Jim has 2x
Then x + 6x + 2x = 54. With this we can get the value of x = 6 and the amount which Jim has = 2 * 6 = 12
Therefore Statement 1 Alone is Sufficient. Answer options could be A or D
Statement 2: The sum of the amounts of money that Jim and Greg have is half the amount that Nick has.
Let Nick have x, then Jim + Greg = x/2
Then x + x/2 = 54. From this we can get the value of x, but we do not know how mu Jim has individually.
Therefore Statement 2 Alone is Insufficient. (option a)