12 hours to cook 5 killigrams how long is needed to cook 3 killograms of meat

The ratio of wooden bats to metal bats in the baseball coach’s bag is 2 to 1. if there are 20 wooden bats, how many metal bats are in the bag?

15/16 as a decimal rounded to the nearest hundredth

If cos(2x) = tan^2(y), show that cos(2y) = tan^2(x).