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.
--------
Question: Problem: find value for x from below equation ? x + 1 = - 3
Options: a. 1, b. - 4, c. - 1, d. 2, e. 3

Answer: b


Question: Problem: a sum of money at simple interest amounts to $ 645 in 3 years and to $ 690 in 4 years. the sum is :
Options: a. $ 153, b. $ 510, c. $ 598, d. $ 549, e. $ 675

Answer: b


Question: Problem: in may mrs lee ' s earnings were 50 percent of the lee family ' s total income. in june mrs lee earned 20 percent more than in may. if the rest of the family ' s income was the same both months, then, in june, mrs lee ' s earnings were approximately what percent of the lee family ' s total income ?
Options: a. 55, b. 56, c. 34, d. 78, e. 23

Answer:
a