Question: Matt can buy key chains in packs of 10 for $20 or in packs of 4 for $12. How much money can he save if he chooses to buy 20 key chains at a lower price?
Answer: The cost of each key chain in packs of 10 for $20 is $20 / 10 = $2. The cost of each key chain in packs of 4 for $12 is $12 / 4 = $3. There is a price difference of $3 - $2 = $1 per key chain between the two choices. By buying 20 key chains at a lower price, Matt can save 20x$1 = $20. The answer is 20.

Question: Frank is practicing a new dance move. It starts with him take 5 steps back, and then 10 steps forward, and then 2 steps back, and then double that amount forward. How many steps forward is Frank from his original starting point?
Answer: Frank stars by taking 10 steps forward from a position 5 steps behind where he started, so he's 10 - 5 = 5 steps forward in total. Frank then takes 2 steps back, meaning he's now 5 - 2 = 3 steps forward in total from where he began. He then takes double the previous amount of 2 steps forward, so he takes 2 * 2 = 4 steps forward. Since Frank was 3 steps forward before that, that means Frank finishes 3 + 4 = 7 steps forward. The answer is 7.

Question: Mara has 40 crayons and 10 percent of her crayons are pink. Luna has 50 crayons and 20 percent of them are pink. In total how many pink crayons do Mara and Luna have?
Answer: Mara has 40 x (10 / 100) = 4 pink crayons. Luna has 50 x (20 / 100) = 10 pink crayons. Together they have 4 + 10 = 14 pink crayons. The answer is 14.

Question: Millie, Monica, and Marius are taking subjects for school. Millie takes three more subjects than Marius, who takes 4 subjects more than Monica. If Monica took 10 subjects, how many subjects all take altogether?
Answer:
If Monica took ten subjects, Marius took 10 + 4 = 14 subjects. Marius and Monica have 14 + 10 = 24 subjects which they've taken. Since Millie is taking three more subjects than Marius, she is taking 14 + 3 = 17 subjects. Together, the three have taken 24 + 17 = 41 subjects. The answer is 41.