Samson is going to another town which is 140 km away. He will use his car that uses ten liters of gasoline for a distance of 70 km. How many liters of gasoline will Samson need for a one-way trip? Give the rationale and then the answer.
Let's think step by step. Samson will need 140 km / 70 km = 2 ten liters of gasoline for a one - way trip to a town. Therefore, he will need a total of 2 x 10 liters = 20 liters of gasoline.. The answer is: 20.

Norris saved $29 in September. He saved $25 in October and $31 in November. Then Hugo spent $75 on an online game. How much money does Norris have left? Give the rationale and then the answer.
Let's think step by step. The total amount of money saved is $29 + $25 + $31 = $85. Norris has $85 - $75 = $10 left.. The answer is: 10.

Tom cannot afford a normal doctor, so he goes to a discount clinic that is 70% cheaper.  It takes two visits, though, instead of 1.  A normal doctor charges $200 for a visit.  How much money does he save? Give the rationale and then the answer.
Let's think step by step. Each of Tom's visits was 200 * .7 = $140 cheaper. So he paid $200 - $140 = $60 per visit. That means he paid $60 * 2 = $120. So he saved $200 - $120 = $80.. The answer is: 80.