Could someone please solve this and explain how to do it?

Look at this pattern ; 1,4,9, number 10000 belongs in this pattern . what’s the place of this number?

Ken earned $128 from his part-time job this summer. he spent 25% of his money on games. he is going to donate 1/6 of the remaining money to charity. how much money will the charity receive?

For her new mp3 player, alicia wants a case that is in. long. the online store shows case sizes in decimal measurements. what length case should she order?