Can someone me with this math question? (also sorry that the paper is a little dirty)

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.

A10 inch cookie cake is divided into 8 slices. what is the area of 3 slices

Student representatives surveyed their classmates on their preference of a school mascot for a new school. the results are shown in the table below. which pair of samples seems most representative of student preference?