My age is five times that of my son. Next year, my son will be eight years old. How old am I now? Give the rationale and then the answer.
Let's think step by step. If the son is going to be eight years old after a year from now, then currently, he is 8 - 1 = 7. Since the father's age is five times that of the son, currently he is 5 * 7 = 35 years old.. The answer is: 35.

The pirates plan to explore 4 islands. Two islands require walking 20 miles per day while the other two islands require 25 miles per day. How many miles will they have to walk if it takes 1.5 days to explore each island? Give the rationale and then the answer.
Let's think step by step. It will take 1.5 days x 2 = 3 days to explore 2 islands. So, the pirates will walk 20 miles x 3 days = 60 miles to explore two islands. The other 2 islands will be explored by walking 25 miles x 3 days = 75 miles. Thus, the pirates will need to walk 60 + 75 = 135 miles to explore the 4 islands.. The answer is: 135.

Andy and Bob went to the canteen to buy snacks. They spent the same amount. Andy bought a can of soda at $1 and two hamburgers at $2 each. Bob ordered two sandwiches for $3 and a can of fruit drink. How much did Bob's fruit drink cost? Give the rationale and then the answer.
Let's think step by step. Two hamburger cost 2 x $2 = $4. So, Andy spent $1 + $4 = $5. Therefore, Bob's fruit drink cost $5 - $3 = $2.. The answer is: 2.