Given a math problem with context and a question and 5 answer choices, the task is to provide the correct answer choice based on the problem. You must choose one of the given answer choices by letter: a, b, c, d, or e; anything else is invalid.

Q: Problem: income and expenditure of a person are in the ratio 7: 6. if the income of the person is rs. 14000, then find his savings ?
Options: a. 500, b. 1000, c. 1500, d. 2000, e. 2500

A: d
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Q: Problem: a merchant sells an item at a 20 % discount, but still makes a gross profit of 20 percent of the cost. what percent of the cost would the gross profit on the item have been if it had been sold without the discount ?
Options: a. 20 %, b. 40 %, c. 50 %, d. 60 %, e. 75 %

A: c
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Q: Problem: p, q and r together earn rs. 1710 in 9 days. p and r can earn rs. 600 in 5 days. q and r in 7 days can earn rs. 910. how much amount does r can earn per day ?
Options: a. s. 40, b. s. 60, c. s. 90, d. s. 100, e. s. 120

A:
b
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