Answer:

72

i think i remember doing this

1)

1/2 - C

1/4 - B

1/8 -D

? - A

1/2*1/4*1/8 = 1/16 of the class got an A

2) 40 lb = 840 oz

840 x* 2 1/4 = 1890 oz

Archie's dog eats 1890 oz of dog food in 2 1/4 years.

a=28

Step-by-step explanation:

use inverse operations

280