[Question]One set of barrettes costs $3 each, and one comb costs $1 each. Kristine buys one set of barrettes and one comb. Crystal buys three sets of barrettes and one comb. How much do the two girls spend altogether?
[Answer]Kristine spends $3 + $1 = $4. Three sets of barrettes cost 3 x $3 = $9. Crystal spends $9 + $1 = $10. Therefore, the two girls spend $4 + $10 = $14. The answer is 14.

[Question]Annie plants 3 pots of basil, 9 pots of rosemary, and 6 pots of thyme. Each basil plant has 4 leaves, each rosemary plant has 18 leaves, and each thyme plant has 30 leaves. How many leaves are there total?
[Answer]First find the total number of basil leaves: 3 pots * 4 leaves / pot = 12 leaves. Then find the total number of rosemary leaves: 9 pots * 18 leaves / pot = 162 leaves. Then find the total number of thyme leaves: 6 pots * 30 leaves / pot = 180 leaves. Then add the number of each type of leaf to find the total number of leaves: 12 leaves + 162 leaves + 180 leaves = 354 leaves. The answer is 354.

[Question]A hot air balloon with 200 balloons is blowing up. After about half an hour, 1/5 of the total number of balloons in the hot air balloon have blown up. After another hour, twice the number of balloons that had already blown up also blow up. How many balloons in the hot air balloon remain intact?
[Answer]After half an hour, the number of balloons that had blown up is 1 / 5 * 200 = 40. The number of balloons that haven't blown up so far is 200 - 40 = 160. In the next hour, 2 * 40 = 80 balloons blow up. The number of balloons that haven't blown up now is 160 - 80 = 80. The answer is 80.

[Question]A forester is planting trees. The forest already has 30 native trees. On Monday he triples the number of total trees in the forest by planting new trees. On Tuesday, he plants a third of the amount he planted on Monday. How many trees has the forester planted in total?
[Answer]
Let M be the number of trees he plants on Monday. On Monday the forest was three times larger from the trees that were originally there and the M trees: 3 * 30 = 30 + M trees. So, 90 = 30 + M. And, M = 60 trees. On Tuesday, he planted 60 trees / 3 = 20 trees. In total, he has planted 60 trees + 20 trees = 80 trees. The answer is 80.