What variables have to be kept the same in this experiment?

It has been two weeks since charles met with daniel, a dietitian, who provided charles with a menu for weight loss. charles and his mother are going back to see daniel again with a chart of the food charles has eaten. the following lists what charles ate in one day: breakfast 1 banana, 1 cup of nonfat milk, 1 egg lunch 1 cup of carrots, 3 oz of steak, 1 apple, 1 cup of nonfat milk dinner 6 oz of skinless chicken, 1 baked potato, 3 oz of broccoli, 1 cup of nonfat milk

Fission of uranium-235 products energy and a. isotopes of smaller elements b. isotopes of larger elements c. lighter isotopes of uranium d. heavier isotopes of uranium

The volume of helium in a blimp is 6.28 x 10^9 millimeters. the density of helium in the blimp is .1786 kilogram/meter^3. find the mass of the helium in the blimp.