What is the pattern between the exponents in a original expression and the exponents in a simplified expression?

Abox contains 1 plain pencil and 4 pens. a second box contains 5 color pencils and 5 crayons. one item from each box is chosen at random. what is the probability that a plain pencil from the first box and a color pencil from the second box are selected? write your answer as a fraction in simplest form.

How many $20 bills do you need to have to make $280

15m is what percent of 60m; 3m; 30m; 1.5 km? the last one is km not m