Well if the number cube goes up to 6 like most number cubes, then the probability would be 3/6 because there are 3 numbers that you want to roll (2, 3, and 5) out of 6 total numbers (1-6). Then 3/6 can be further simplified to 1/2. So the answer should be 1/2.
The awnser would be 210 because 7 times 10 times 3 is 210