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.

[Q]: Question: A warehouse is labeling computer inventory with 3-digit codes. Each code is to consist of four digits between the numbers 0 and 9. The manager is debating whether to allow any 3-digit codes to have leading zero's before a non-zero number is used. If not allowed, then numbers like0025cannot be used.
The manager wants to measure the magnitude of the number of 3-digit code possibilities that are lost if he disallows the use of leading zero's. How many such codes would be lost?

 Option A: 981

 Option B: 1000

 Option C: 1011

 Option D: 1101

 Option E: 100
[A]: Option E


[Q]: Question: A patient was given five pills which he is required to take one after every twenty minutes.
How long can the pills run for him?

 Option A: 1 hour

 Option B: 1 hour 20 minutes

 Option C: 1 hour 30 minutes

 Option D: 1 hour 35 minutes

 Option E: 1 hour 40 minutes
[A]: Option B


[Q]: Question: A person saved $10 in buying an item on sale. If he spent $100 for the item, approximately how much percent he saved in the transaction?

 Option A: 8%

 Option B: 10%

 Option C: 2%

 Option D: 5%

 Option E: 6%
[A]:
Option B