20. On four tests, each marked out of 100, my mean score was 85 . What is the lowest mark I could have scored on any one test?

\( (-\frac{8}{9}).(-\frac{27}{2}) \)

18. Isaac bought three packages of nuts He bought one package of peanuts the weighed 3.07 pounds. He also bought two packages of pecans that weighed 1.46 pounds and 1.5 pounds. Did the peanuts or the pecans weigh more? Hours much more?

15. \( \frac{1}{15}+\frac{6}{5} \div \frac{12}{7} \)

b) \( 1 \div \frac{2}{9} \)

Mrs. Andrew's classroom has 4 rows of desks with 3 desks in each row. She placed 2 pencils on each desk. How many pencils did Mrs. Andrew place on the desks altogether?