Please help its a test

Plz hurry evaluate the expression a+b where a=8 and b=19

Novak gives 9 packs of paper to a group of 5 students. if the group shares the paper equally how many packs of paper does each student get. write the a answer as a mixed number

The diameter of the moon is about 3500 km. approximate the surface area of the moon using the formula for the surface area of a sphere, s = 4? r^2. write your answer in scientific notation.