Answer:
Step-by-step explanation:
Area = 84sqaure inch
Width = 2 1/2inch = 5/2inch
Area = l × width
So: 84 = l × 5/2
168 = 5l
l =>168/5
l = 33 3/5
I think it is C sorry if i am wrong but i am confident
Convert to base 10
2×3² + 0×3¹ + 1×3^0 = 18 + 0 +1 = 19 base 10
so convert 19 to base 8
19 base 10 = 23 base 8
D is your answer