[Question]: Arthur knows that he needs to finish 800 pages of reading over the summer. He has read 80% of a 500-page book and 1/5 of a 1000 page book. How many more pages does he need to reach to meet his goal?
[Answer]: He read 400 pages from the 500 page book because 500 x .8 = 400. He read 200 pages from the 1000 page book because 1000 x (1 / 5) = 200. He has read 600 pages in total. He needs to read 200 more pages to reach 800 pages because 800 - 600 = 200.
So the answer is 200.

[Question]: Ephraim has two machines that make necklaces for his store. On Sunday the first machine made 45 necklaces. The second machine made 2.4 times as many necklaces as the first machine. How many necklaces were made in total on Sunday?
[Answer]: The second machine made 2.4 times as many necklaces as the first machine, so the second machine made 2.4 * 45 = 108 necklaces on Sunday. In total, 45 + 108 = 153 necklaces were made on Sunday.
So the answer is 153.

[Question]: Wendy went to the dentist for a cleaning, two fillings, and a tooth extraction. The dentist charges $70 for a cleaning and $120 for a filling. Wendy's dentist bill was five times the cost of a filling. What did Wendy pay for the tooth extraction?
[Answer]:
Wendy's dentist bill was 5 * $120 = $600. She got two fillings at a cost of 2 * $120 = $240. Thus, Wendy paid $600 - $240 - $70 = $290 for the tooth extraction.
So the answer is 290.