Answer:
126.18 hr
Explanation:
Data given:
1 mL of water = 20 drops
count rate = 10 drops/s
time in hours for one gallon = ?
Solution:
First we calculate number of mL (milliliter) of water in gallon
As we know
1 gallon = 3785.4 mL
As,
1 galon consist of 3785.4 mL of water, so now we count number of drops that contain 3785.4 mL of water
As we Know 1 mL water contain 20 drops then 3785.4 mL of water contain how many drops:
Apply unity formula
1 mL water ≅ 20 drops
3785.4 mL water ≅ X drops
Do cross multiplication
X drops of water = 20 drops x 3785.4 mL / 1 mL
X drops of water = 75708 drops
So, we come to know that one gallon contain 75708 drops of water and we have to calculate the time in hour to count these drops
First we calculate time in seconds
As we Know 10 drops water count in one second then how many seconds it will take to count 75708 drops
Apply unity formula
1 second ≅ 10 drops
X second ≅ 75708 drops
Do cross multiplication
X second = 1 second x 75708 drops / 10 drops
X second = 7570.8 second
So it take 7570.8 second to count 1 gallon water drops
Now convert seconds to hours
As,
60 seconds = 1 hr
7570.8 second = 7570.8 / 60 = 126.18 hr
So it take 126.18 hr to count 1 gallon water drops.