1. Remember, "percentage" is a fancy word for saying "/100", (i've been saying that a lot lately). so 90% means 90/100 and 65% means 65/100 and so on. also, "of" in math means multiply. so when they say a car of the train is 90% full, it means there are 90% of 20 people in the car, which means there are 90/100 * 20 people in the car. ok, now to do the question.

90% of 20 is 0.9*20 = 18. so we have 5 cars with 18 people

65% of 20 is 0.65*20 = 13, so we have 3 cars with 13 people

so we have 5*18 + 3*13 = 129 people in all.

it takes 20 people to fill one car, so the amount of cars we can fill will be 129/20 cars = 6.45 cars. since we are only concerned with how many cars we can fill, the answer is 6. 6 cars will be filled with 20 people each if the people were rearranged.

2. Use each of the digits 1,2,4,5,8, and 9 once to creat the greatest possible value of the following expression. The mixed numbers have to be in proper form, without being renamed.

( 9) ( 2)/3-( 1) ( 5)/6+7 ( 4)/(5 )