It appears to be always wrong even if I type in the correct answer!

Tell us what’s happening:

Your code so far

// Only change code below this line
var a=6;
var b=15;
var c="I am a";
// Only change code above this line

a = a + 1;
b = b + 5;
c = c + " String!";

Your browser information:

User Agent is: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/70.0.3538.102 Safari/537.36 Edge/18.18363.

Challenge: Understanding Uninitialized Variables

Link to the challenge:

Where did you get 6 and 15 from?

Careful. You need to set the initial value of a so the final value is 6