Help? brainliest if i can..

The sum of two numbers is 12 and their difference is 18 what are the two numbers

Gravel is being dumped from a conveyor belt at a rate of 25 ft3/min, and its coarseness is such that it forms a pile in the shape of a cone whose base diameter and height are always equal. how fast is the height of the pile increasing when the pile is 14 ft high? (round your answer to two decimal places.) ft/min

Use your knowledge of the binary number system to write each binary number as a decimal number. a) 1001 base 2= base 10 b) 1101 base 2 = base 10