Buying a toaster requires an insurance plan that is 20% of the MSRP, plus a mandatory state tax rate of 50% after the insurance plan calculation. Jon chooses to buy a toaster that costs $30 at MSRP. What is the total he must pay? Give the rationale and then the answer.
Let's think step by step. The insurance plan costs $30 * 0.2 = $6. The pre - state tax total is $30 + $6 = $36. State tax will be $36 * 0.5 = $18. Jon needs to pay $18 + $36 = $54 for his new toaster.. The answer is: 54.

After eating half of the number of fruits he had, Martin remained with twice as many oranges as limes. If he has 50 oranges now, how many fruits did he initially have? Give the rationale and then the answer.
Let's think step by step. Since the number of oranges that Martin has now is twice the number of limes, there are 50 / 2 = 25 limes. The number of fruits she has now is 50 oranges + 25 limes = 75. If she had eaten half of the number of fruits that she had, initially Martin had 2 * 75 = 150 fruits.. The answer is: 150.

Bertha plays tennis. Every ten games, one of her tennis balls wears out. Every five games, she loses a ball. Every four games, she buys a canister of three balls. She started with two balls and gave one to her partner. After twenty games, how many tennis balls does she have? Give the rationale and then the answer.

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
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Let's think step by step. Bertha wears out 20 / 10 = 2 tennis balls in 20 games. She loses 20 / 5 = 4 tennis balls in 20 games. She buys canisters of 3 * 20 / 4 = 15 tennis balls in 20 games. Bertha started with 2 balls and gave 1 away, so she has 2 + 15 - 2 - 4 - 1 = 10 tennis balls after twenty games.. The answer is: 10.