Math sequences hw help

Im having trouble solving these, basically I don't get how to do sequences. please explain step by step, thanks!!

2. The least integer of a list of consecutive odd integers is -35. If the sum of these integers is 37, how many integers are in this list?

3. The hourly wages of two workers are consecutive even integers. If the higher paid worker's hourly wage is x, what is the sum of both workers' hourly wages?

4. The sum of the integers from 40 to 60, inclusive, is, 1050. What is the sum of the integers from 60 to 80, inclusive?

5. Daniel wants to save at least 20 dollars. On the first day he puts one penny into a can. The second day he puts 2 pennies into the same can. On the nth day he puts n pennies into the same can. How many days does he need until he has 20 dollars in the can? (1 dollar = 100 pennies)

2) We know that the list consists of odd integers and that -35 is the smallest number on the list, so -33 must be the second, -31 must be the third, etc. Note that if 35 is the last number on the list, the sum of all the numbers must be 0, since every positive number has a negative "pair" and the just cancel out (-35 + 35 = 0, -33 + 33 = 0, and so on). The problem tells us that the sum of all the numbers of the list is 37, so to get from 0 to 37, we have to add 37, which (conveniently) happens to be the next odd number after 35, where are list previously stopped. So the list consists of all the odd numbers between -35 and 37, inclusive. All that remains is to find out how many numbers are on that list. Recall that to find the nth term in a sequence, An, we must use the "formula" An = A1 + d(n - 1). We already know that An is 37, A1 (the first term in the sequence) is -35, and d, the common difference is 2 (since to go from one even number to the next you must add 2), so all that remains is to solve for n. After doing a bit of algebra, we find that n = 37, so there are 37 integers.