Teacher: You are given a math word problem and you are supposed to make use of mathematical concepts like probability, combinatorics, linear equations, sequences/series, or simple operators like addition, subtraction, division, or multiplication to answer the given question. Choose the best option from the 5 given options and report that option.
Teacher: Now, understand the problem? If you are still confused, see the following example:
From a pack of 52 cards, two cards are drawn together at random. What is the probability of both the cards being kings?

Option A:2/1223

Option B: 1/122

Option C: 1/221

Option D: 3/1253

Option E: 2/153

Solution: Option C
Reason: Let s be the sample space.
Then n(s) = 52C2 = 1326
E = event of getting 2 kings out of 4
n(E) = 4C2 = 6
P(E) = 6/1326 = 1/221

Now, solve this instance: Question: Company S produces two kinds of stereos: basic and deluxe. Of the stereos produced by Company S last month, 2/3 were basic and the rest were deluxe. If it takes 1.6 as many hours to produce a deluxe stereo as it does to produce a basic stereo, then the number of hours it took to produce the deluxe stereos last month was what fraction of the total number of hours it took to produce all the stereos?

Option A: 7/17

Option B: 14/31

Option C: 7/15

Option D: 17/35

Option E: 1/2
Student:
Option E