Elon has 10 more teslas than Sam who has half the number of teslas as Chris. Chris has 6 teslas. How many teslas does Elon have? Give the rationale and then the answer.
Let's think step by step. Sam has half the number of Chris: 6 / 2 = 3 teslas. Elon has 10 more than Sam: 10 + 3 = 13 teslas.. The answer is: 13.

A conference center has six rooms. Each room can hold up to 80 people. Today, the conference center is only 2/3 full. How many people are in the conference center? Give the rationale and then the answer.
Let's think step by step. The conference center can hold up to 80 x 6 = 480 people. Today, there are 480 x 2 / 3 = 320 people in the conference center.. The answer is: 320.

John decides to take up illustration. He draws and colors 10 pictures. It takes him 2 hours to draw each picture and 30% less time to color each picture. How long does he spend on all the pictures? Give the rationale and then the answer.
Let's think step by step. The coloring takes 2 * .3 = .6 hours less than the drawing. So it takes 2 - .6 = 1.4 hours per picture. So it takes him 2 + 1.4 = 3.4 hours per picture. That means it takes 3.4 * 10 = 34 hours.. The answer is: 34.