Oscar wants to train for a marathon. He plans to add 2/3 of a mile each week until he reaches a 20-mile run. How many weeks before the marathon should he start training if he has already run 2 miles? Give the rationale and then the answer.
Let's think step by step. Oscar needs to increase his maximum running time from 20 - 2 = 18 miles. Oscar will need a total of 18 / ( 2 / 3 ) = 27 weeks to prepare.. The answer is: 27.

Bob and Kate went to a restaurant for dinner. After they were done eating the waitress gave a $30 bill to Bob and a $25 bill to Kate, but told them they were eligible for special discounts; 5% for Bob, 2% for Kate. Considering the discounts, how much do they have to pay in total? Give the rationale and then the answer.
Let's think step by step. 5% of $30 is (5 / 100) * 30 = $1.5. The dollar amount of Bob's discount is $1.5 so he will pay $30 - $1.5 = $28.5. 2% of $25 is (2 / 100) * $25 = $0.5. The dollar amount of Kate's discount is $0.5 so she will pay $25 - $0.5 = $24.5. Altogether they will pay $28.5 + $24.5 = $53.. The answer is: 53.

Aaron has four times as many cows as does Matthews. Together, they have 30 more cows than Marovich. If Matthews has 60 cows, how many cows do the three have altogether? Give the rationale and then the answer.
Let's think step by step. If Matthews has 60 cows, Aaron has 4 * 60 = 240 cows. Together, Aaron and Matthews have 240 + 60 = 300 cows. Since Marovich has 30 fewer cows than the combined number of cows that Aaron and Matthews have, Marovich has 300 - 30 = 270 cows. Altogether, the three have 270 + 300 = 570 cows.. The answer is: 570.