I agree with copeg, but if you really have no idea where to start, break it down even further. You're trying to figure out the value in dollars and cents of the coins in the jar, right? Start simple, figure out the value in cents. You'll need separate integer variables for each type of coin that are equal to the value of that coin in cents. Then you'll need to specify (or have the user specify) how many of each coin there are in the jar. Add the coins up and you get the value in cents. So how would you print it out as dollars and cents? Well, as a hint, maybe try using the printf() method. If you haven't learned that, think about what kind of variable would use the same format as dollars and cents (i.e. a decimal point followed by two place values) and recognize that dollars=100*cents.
Feel free to PM me if you want with any specific questions. The best way to go about any problem is to break it down into small pieces and solve it one step at a time. Good luck!