Shoshanna creates a volcano model. the volcano sits on 7 4/5 pounds. the entire model, including the board, weighs, 12 1/2 pounds. how many pounds does shoshanna’s model weigh? Any pleas

In a two-digit number the units' digit is 7 more than the tens' digit. the number with digits reversed is three times as large as the sum of the original number and the two digits. find the number.