Nth term (formula) of 1² , 2² ,3² ,4² ,5²

Rachel reads 1/5 of the pages of a book plus 12 pages on the first day. on the second day, she reads 1/4 of the remaining pages plus 15 pages. on the third day, she reads 1/3 of the remaining pages plus 18 pages. on the fourth day, she reads the remaining 70 pages. how many total pages are in the book?

Prove that quadrilateral is a rhombus.

Annabelle's homework is 75% it took her three hours how long should she estimate it will take her to complete her homework.