family maths challenge

Paul has two dozen carrot cookies. He will eat three cookies on Sunday. On every day that follows, he will eat a number of cookies that is one greater than the day before. On what day will he find that he doesn’t have enough cookies to follow this procedure?

On Sunday - 3 cookies eaten (leaves 21 cookies)
On Monday- 4 cookies eaten (leaves 17 cookies)
On Tuesday- 5 cookies eaten (leaves 12 cookies)
On Wednesday-6 cookies eaten (leaves 6 cookies)
On Thursday-7 cookies.............not enough cookies left.
Paul would realise on Thursday that he didn't have enough cookies left to follow the procedure.