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A large fresh water reservoir has two types of drainage system: small pipes and large pipes.
6 large pipes, on their own, can drain the reservoir in 12 hours.
3 large pipes and 9 small pipes, at the same time, can drain the reservoir in 8 hours.
How long will 5 small pipes, on their own, take to drain the reservoir?
Find here the exact time required!
Here is the question!
Let T be the capacity of the tank. Let L be the large pipe and S be the small pipe.
T/6L = 12
L = T/72
T/(3L + 9S) = 8
Putting L = T/72,
S = T/108
Hence T/5S = 108/5 gives S = 21.6 hours.
To conclude, small pipes require 21.6 hours i.e. 21 hours and 36 minutes to drain the reservoir.
Someone drove from Aardvark to Beeville.
On the first, day they traveled 1/3 of the distance.
On day two, they traveled 1/2 of the remaining distance.
On day three, they traveled 2/3 of the remaining distance.
On day four, after covering 3/4 of the remaining distance, they were still 5 miles away from Beeville.
How many miles had they covered so far?
Know the total distance traveled!
Click for the question!
We need to start in reverse.
In last part after covering 3/4 still 5 miles left which accounts for 1/4 of remaining distance. Hence, 20 miles were left at the start of DAY 4.
On DAY 3, 2/3rd covered leaving 20 miles for DAY 4. That means 20 miles distance is remaining 1/3rd. Hence, at the start of DAY 3, 60 miles were left.
On DAY 2, 1/2 of covered leaving 60 miles for DAY 2. So that means 60 miles distance is remaining 1/2. So at the start of DAY 2, 120 miles yet to be covered.
On DAY 1, 1/3 of covered leaving 120 miles for DAY 2. Meaning 120 miles distance is remaining 2/3. Hence, 180 miles yet to be covered at the start of DAY 1.
Out of 180 miles, 175 covered in 4 days still 5 miles left.
