How to solve Code Coach Problems? I tried to solve but didn't understand about what does it mean by test cases.

Answer 1

test cases are prepared tests of your program. They just checks if your program gives proper output, for instance when you have to write program that must return sum of two numbers read from input, then :
test case 1 gives on input 3 and 78, and checks if output of your program is 81
test case 2 gives on input 66 and 42 and checks if output is 108
and so on...
if something goes wrong then your code is considered invalid

Answer 2

But all the test cases should be typed at one go ?
Like whole program should be done at the start itself ? Szwendacz

Answer 3

test cases are not your job they are already prepared by sololearn and if you just do what is told in code coach task and click run then these tests will start and validate your program