One of the students wants to send postcards to 18 of her friends. A package Contain 7 postcards. How many packages must she buy

If the measure of angle 1 is 110 degrees and the measure of angle 3 is (2 x+10 degree), what is the value of x?

Two angles are complementary. the large angle is 36 more than the smaller angle. what is the measure of the large angle?

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.