Question: Patrick is half the age of his elder brother Robert. If Robert will turn 30 after 2 years, how old is Patrick now?
Answer: The age of Robert now is 30 - 2 = 28 years old. So, Patrick is 28 / 2 = 14 years old. The answer is 14.

Question: Mary has 5 green crayons and 8 blue crayons of different shades. If she gives out 3 green crayons and 1 blue crayon to Becky, how many crayons does she have left?
Answer: She had 5 + 8 = 13 crayons to start with. She gave out 3 + 1 = 4 crayons to Becky. She will have 13 - 4 = 9 crayons left. The answer is 9.

Question: Nico borrows 3 books from the library on Monday. On Monday, he reads the first book with a total of 20 pages. On Tuesday, he reads the second book with a total of 12 pages. On Wednesday, he reads the third book. If he has read a total of 51 pages from Monday to Wednesday, how many pages did he read on Wednesday?
Answer: From Monday to Tuesday, Nico reads a total of 20 + 12 = 32 pages. On Wednesday, he read a total of 51 - 32 = 19 pages. The answer is 19.

Question: Brianna started out with a bag of 24 marbles. She lost four marbles through a hole in the bag. Then, she gave away twice as many marbles as she had lost through the hole in the bag. Finally, her dog ate half as many marbles as Brianna had lost through the hole in the bag. How many marbles did Brianna have remaining?
Answer:
Brianna gave away twice as many marbles as she had lost, or a total of 2 * 4 = 8 marbles. Her dog ate half as many marbles as Brianna had lost through the hole in the bag, or 4 / 2 = 2 marbles. If she started with 24 marbles, then the number of marbles remaining is 24 - 4 - 8 - 2 = 10 marbles. The answer is 10.