The sum of the first n terms of an arithmetic sequence a1,a2,a3, ...,an is 1/2n(a1+an), where a1 and an area the first and nth terms of the sequence, respectively. What is the sum of the odd integers from 1 to 99 inclusive?

Janie has $3. she earns $1.20 for each chore she does and can do fractions of chores. she wants to earn enough money to buy a cd for $13.50. write an inequality to determine the number of chores, c, janie could do to have enough money to buy the cd.

Zach spent 2/3 hour reading on friday a 11/3 hlurs reading on saturday. how much more time did he read on saturday tha on friday

Ineed with question three. i don't understand how i'm supposed to achieve 3 marks.