n00b questions (1) circuit analysis/problem solving

Hi,
First,is problem solving important and useful?

Second :
I got this problem from a book I have...

"five coulombs of charge pass through the element in Fig1 form point A to point B. if the energy ABSORBED by th element is 120 J,determine the voltage across the element"

The charge enters the negative terminal and leaves the positive terminal (as u see in the figure) which means the element is supplying power according to "the passive sign convention" ,but the problem says it's absorbing energy....hmmm :?: :?

Thanks

I have no idea what this "passive sign convention" is but you don't need it to solve the problem. The formula you want is V=W/Q. W is expressed in Joules and Q is expressed in Coulombs.

the "covention" i read in the same book which is "basic engineering " by david Irwin says that if a current enters a negative terminal and leaves the postive one of an element then it means it's supplying but it says in the question it's absorbing,that's what makes me confused...