UnknownDeveloper - 1 year ago 73
Javascript Question

# Same Birthday Probabilty code Value is not what was expected

There is a codewars challenge called the Same Birthday Probabilty which challenge is:

Given n number of people in a room, calculate the probability that any
two people in that room have the same birthday (assume 365 days every
year = ignore leap year). Answers should be two decimals unless whole
(0 or 1) eg 0.05

and I did the folloowing for this challenge:

``````function calculateProbability(n){
var result = 0;
for(i=1;i<n;i++){
var total = (365 - i) / 365
result = result * total
}
return Math.round(result)
}

calculateProbability()
``````

With and without the
`Math.round`
method but I always get:

✘ Value is not what was expected

and that is the only error.

This is what the test cases are

``````Test.expect(calculateProbability(5)==0.03);
Test.expect(calculateProbability(1000)==1);
``````

Thank you

First of all you should change result to `1` since multiplying by `0` always yields zero. The result you are calculating is the complement of the solution, it is the probability that `n` people have different birthdays. Finally you are not rounding your number to two decimals.
``````function calculateProbability(n){