Question
Three pipes A, B and C can fill/empty a tank. A can fill
it in 12 hours, B in 15 hours, and C can empty a full tank in 20 hours. All three pipes are opened together. After some time, pipe C is closed and A and B together fill the remaining tank in 5 hours. If the tank is exactly full at the end, for how many hours was pipe C kept open?Solution
ATQ, Filling rates: A = 1/12, B = 1/15, C (emptying) = −1/20 (per hour). A + B = 1/12 + 1/15 = (5 + 4)/60 = 9/60 = 3/20. A + B + C = 3/20 − 1/20 = 2/20 = 1/10. Let C be open for x hours (all three working). Volume filled in this time = x × (1/10) = x/10. After C is closed, A + B work for 5 hours: Volume filled = 5 × (3/20) = 15/20 = 3/4. Total volume = 1 ⇒ x/10 + 3/4 = 1 ⇒ x/10 = 1 − 3/4 = 1/4 ⇒ x = 2.5 hours.
A paper is folded and cut as shown below. How will it appear when unfolded?
The sequence of folding a piece of paper and the manner in which the folded paper has been cut is shown in the following figures. How would this paper l...
The sequence of folding a piece of paper and the manner in Which the folded paper has cut is shown in the following figures. How would this paper look w...
A piece of paper is folded and cut as shown below in the question figure. How will it appear when unfolded?
In the question, assuming the given statements to be true, find which of the conclusion (s) among given two conclusions is /are definitely true and the...
A paper is folded and cut as shown in the following figures. How would this paper look when unfolded?
The sequence of folding a piece of paper and the manner in which the folded paper has been cut is shown in the following figures. How would this paper l...
- The sequence of folding a piece of paper and the manner in which, it is folded has been cut as shown in the following figure. How would this paper look whe...
