What can we use to measure liquid and solid

The difference of 2 numbers is 21 and the quotient of the equation is 4 then what are the two numbers?

Which is the standard form for this number? (4 x 1 100 ) + (8 x 1 1,000 ) + ( 3 x 1 100,000 ) ? a) 0.004803 b) 0.04803 c) 0.0483 d) 0.483

Which of the following would be a good name for the function that takes the weight of a box and returns the energy needed to lift it?