Ming needs to play for 15 hours to get 500 points. They gave him 200 for signing up, so 500-200=300 more points needed. 300 divided by 20= 15 more hours.
So we can call first number "n"
Then all five integers would be n, n+1, n+2, n+3, n+4
So sum of them would be 5n + 10 = 100
Now you can solve for n:
5n + 10 = 100
5n = 90
n = 18
Verify: 18 + 19 + 20 + 21 + 22 = 100. All good.
So answer is 18
