What is the average of the first 99 counting numbers?

How do you solve this without having to add all the numbers and divide by 99?

A college cafeteria pays student cashiers $10.20 per hour. Cashiers earn an additional $1.30 per hour for each hour worked over 35 hours per week. A cashier worked 40 hours one week and 38 hours the second week.

1. Crystal drew a quadrilateral with two sets of parallel, equal sides. Which shape did she draw?

Is 3x • 6x + 1 + 42 + - 2x equivalent to 13x + 45

James cut 1 1/4 dozen flower for a bouquet. Gwen added 1 2/4 dozen flowers to the bouquet. How many dozen flowers are there altogether?

After a sleepover, 3/4 of a large pepperoni remained. The next day, he ate 1/8 of what was left over. What fraction of a large pizza did he eat? How much pizza remained after he ate some?

William earns $15 each time (t) he mows a lawn. Which equation can be used to determine how many lawns William mowed if he earned $75?

What is the historical estimate of beta for your stock? what is the range of the estimate with 67% probability? with 95% probability?

A pet store had 6 puppies selling for 104 each and 12 kittens selling for 24 each. Today only 2 puppies and 8 kittens were left. In dollar terms, what was the ratio of the sales of puppies to kittens?

Find the sum: (2x^2 + x + 13) + (3x^2 + 2x + 1)

How to find the unknown measure of a rectangle whose area is 91 and width is 7.