Question
Two pipes A and B can fill a tank in 12 min., and 16
min, respectively. If both the pipes are opened simultaneously, after how much time A should be closed so that the tank is full in 12 minutes?Solution
Let A be closed after x minutes. Then, Part filled by (A + B) in x min. + part filled by B in (12 – x) min. = 1 x (1/12 + 1/16 ) + (12 – x ) × 1/16 = 1 ⟹ (7 x)/48 + (12 - x)/16 = 1 ⟹ (7 x)/48 + 3/4 - x/16 = 1 ⟹ (4 x)/48 = 1/4 ∴ x = 3 ∴ Hence, A must be closed after 3 minutes.
A paper has been folded and cut as shown. Figure (X) shows the manner in which the folded paper has been cut. Choose a figure which would most closely r...
In the following question, select the figure which can be placed at the sign of question mark (?) from the given alternatives.
What should come in place of ? in the given series?
41 45 54 70 95 ?
Eight classmates P, Q, R, S, T, U, V and W are sitting around a circular table facing the centre, but not necessarily in the same order. W sits exactly ...
Given below is a statement followed by some conclusions. You have to take the given statement to be true even if it seems to be at variance with the com...
What should come in place of '?' in the given series?
10 59 353 ? 12701 76205 457229
Select the set in which the numbers are related in the same way as are the numbers of the following sets.
(NOTE : Operations should be performed ...
Rohit travels 10 km to the east from his shop, then turns left and travels 21 km. He again turns left and travels 30 km to reach his house. What is the ...
Rogerio, in search of an internet café, walked 30 m due North. He turned right and walked 18 m. He again turned right and walked 30 m. Finally, he turn...
A boy pointing to a woman said, "She is the sister of my grandmother's only son-in-law." What is the relation between that boy's sister?
Relevant for Exams:
