Answer: 40
Explanation:
So, we know that the ending number is 1300. We get that when we multiply the starting number by 30 and then add 100. So let's subtract 1300-100. We will get 1200. We are now one step closer. Now we know that dividing is the opposite of multiplying, so we can do 1200/30, which equals 40. We are not sure that is correct, so let's double-check. 40x30 equals 1200. 1200+100 equals 1300. TA-DA!