Which is greater or equal 52,800 cm or 1 km

Fred bought 3 cd’s for $16.50 is this multiplication division subtraction or addition

Ared balloon starts at 7.3 meters off the ground and rises at 2.6 meters per second. a blue balloon starts at 12.4 meters off the ground and rises at 1.5 meters per second. when will the balloons be at the same height?

Is the product of two rational numbers irrational or rational? first, make a hypothesis by multiplying two rational numbers. then, use variables such as x=a/b and y=c/d and the closure property of integers to prove your hypothesis.