## Microsoft Interview Question

Software Engineers**Team:**Windows

**Country:**United States

**Interview Type:**Phone Interview

I think the option (a would maximize his chance

because,

for option (a

prob(driving red car AND listening to POP music AND arriving earlier on Friday) =

0.4*0.4*0.3 = 4.8%

for option (b

= 0.3 * 0.3 * 0.3 = 2.7%

Your idea is good, however it should not be calculated in that way. If we do like that, then the prob(red, pop, arrive not earlier on fri.) = 0.4 * 0.4 * 0.7 is also larger than black&rock.

The problem is P(Red&pop|Fri) != P(Fri|Red&pop).

if we assume the conditions are mutual independent, P(Fri|Red&pop) = P(Fri&Red&pop) / P(Red&pop) = P(Fri), so they are all the same.

a.) would maximize his chances to reach office early

Total cases=10

a.)probability=probability of driving red car *probability of listening to POP music * probability of reaching office early on friday = 4/10 * 4/10 * 3/10=0.048

b.)probability=probability of driving blue car *probability of listening to rock music * probability of reaching office early on teusday= 3/10 * 3/10 * 3/10=0.027

Probability for option a = 0.4+0.4+0.3 = 1.1

Probability for option b = 0.3+0.3+0.3 = 0.9

Ideal total probability = ideal option a probability + ideal option b probability = 1+1 = 2

obtained probability = option a probability + option b probability = 1.1+0.9=2

Percentage probability:

Option a percentage = 1.1/2 = 55%

Option b percentage = 0.9/2 = 45%

So option a is optimal with 55% probability

I thinks both of question are "whatever" because the color of car and music type do not related with the result.

Based on observation, we got 30% probability to reaching at office before the time. So whatever the color of car which John drives or whatever the music John listening. John will has 30% probability to reaching at office on Friday and Tuesday.

The result has NO related with the color of car and the music of listening. The only thing which will effects the result is date.

- vista.shao August 14, 2015So John will have 30% probability reaching office before the time on Tuesday and Friday.