To get a number ending in 1- first can be any of 8 and second any of 7. So there are 8x7=56. But it will be the same for numbers ending in 3,5,7 or 9.
Hence answer is 56x5= 280
Can you think of a sequence of steps to construct such a number? E.g., "at first I choose the last digit, then ..." Try to calculate in how many ways each step can be done. Then usually you have to multiply the numbers for each step. It is important that all possible numbers can be constructed using these steps, and no number is constructed twice using different choices.