A rational number is a number that can be expressed as the relationship between two integers. Fractions and decimals will either repeat or end. An example is 5. Maybe 7. 53573 is an example as well. So is 5/1, because 5 and 1 are both integers. so is 7.5, because 7 and 5 are both integers, and it ends (the numbers after the decimal doesn't keep going). Your answer is 7.8, because it ends.
You have to Multiply times 3...
12•3=36
36/12=3
165\15= number of tubs
165 divided by 15 equals the amount of the tubs that he sold.
(I assume the two different name things, isaac&dominic, is a mistake since there isnt any information for Dominic)
60 = 0.20x
60/0.20 = x
300 = x <== so 60 minutes is 20% of 300 minutes