Answer:
A B and D
Step-by-step explanation:
So basically you need to ......
Hope it helps
Answer:
Speed of boat in still water is 6km/h
Speed of current is 4km/h
Step-by-step explanation:
We know speed = distance / time
Let the speed of boat in still water be x
Let the speed of current be y
Hence the speed of boat, down stream = 
Distance downstream = 20km
Time taken = 2 hours
We have

......(1)
Speed of boat upstream = 
Distance upstream = 4
Time taken = 2
We have

...(2)
Adding (1) & (2)


Substituting in (1) we get

The ratio of people that can be served to milligrams of baking soda needed is:
Serving : Baking Soda
2 : 1600mg
Since you want 10 people, you can multiply this ratio by 5:5 to get
10 people served = 8000mg needed
8000mg = 8 grams