Step-by-step explanation:

D=426-48(21)
I got 18 days.
So, D=18
Hope this helps! :)
Answer:
The answer is on this link:
https://www.slader.com/discussion/question/while-sailing-toward-the-statue-of-liberty-a-sailor-in-a-boat-observed-that-at-a-certain-point-the-a/
Answer is 280
First, find A = 35% (100% less the three known percents = 35
Second, find ratio of B
20% of x = 160
Divide 160/.20 to isolate x
X=800 (total biscuits)
Now take A percentage x 800 biscuits
800 x 35% = 280 people chose biscuit A