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.

[EX Q]: Problem: the probability of two events a and b are 0.25 and 0.40 respectively. the probability that both a and b occur is 0.15. the probability that neither a nor b occur is _________
Options: a. 0.45, b. 0.4, c. 0.5, d. 0.05, e. 0.6
[EX A]: c

[EX Q]: Problem: at garage sale, all of the prices of the items sold were different. if the price of a radio sold at the garage sale was both the 9 th highest price and the 35 th lowest price among the prices of the items sold, how many items were sold at the garage sale ?
Options: a. 43, b. 28, c. 44, d. 49, e. 46
[EX A]: a

[EX Q]: Problem: a cone of height 9 cm with diameter of its base 18 cm is carved out from a wooden solid sphere of radius 9 cm. the percentage of the wood wasted is :
Options: ['a. 45 %', 'b. 56 %', 'c. 67 %', 'd. 75 %', 'e. none of these']
[EX A]:
d