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.

Problem: a man spends 2 / 5 of his salary on house rent, 3 / 10 of his salary on food and 1 / 8 of his salary on convenience he has rs. 1400 left with him, find his expenditure on food and conveyance.
Options: a. 1000, b. 3000, c. 4000, d. 2000, e. 5000
a

Problem: a sells a bicycle to b and makes a profit of 50 %. b sells the same bicycle to c at a profit of 25 %. if the final s. p. of the bicycle was rs. 225, find out the cost price of the bicycle for a.
Options: a. 237, b. 126, c. 971, d. 611, e. 120
e

Problem: a waiter ' s salary consists of his salary and tips. during one week his tips were 7 / 4 of his salary. what fraction of his income came from tips ?
Options: a. 4 / 9, b. 5 / 4, c. 5 / 8, d. 5 / 9, e. 7 / 11

e