The total weight is 2 1/2 lbs
Rock A is 1/7 of the total weight....so it is 1/7 of 2 1/2 lbs..." of " means multiply
1/7 * 2 1/2 =
1/7 * 5/2 =
5/14 lbs <==
Volume = length x width x height
Volume = 3 1/4 x 2 x 1 3/4 = 11 3/8 cubic feet
Answer:
Answer is B
Step-by-step explanation:



48 + 24 + 12 + 6 = 90 inches or <span>3*(16+8+4+2) = 90 will be the right answer.</span>