Question
Three pipes P, Q and R can fill a cistern in 40 minutes,
80 minutes and 120 minutes, respectively. Initially, all the pipes are opened. After how much time (in minutes) should the pipes Q and R be turned off so that the cistern will be completely filled in just half an hour?Solution
Assume total work = 240 units (LCM of 40, 80, 120).
Efficiencies: P = 6 units/min, Q = 3 units/min, R = 2 units/min. Let Q and R be turned off after x minutes. Work in first x minutes = (6 + 3 + 2 ) × x = 11x Work in remaining 30 − x minutes by P = 6(30 − x) 11 x + 6 ( 30 − x ) = 240 ⇒ 11 x + 180 − 6 x = 240 ⇒ 5 x = 60 ⇒ x = 12
Which of the given figures when placed in the 5th position would continue the series that is established by the first four figures?
Select the figure from the alternatives which will complete the pattern in given question figure.
Read the given statements and conclusions carefully. Assuming that the information given in the statements is true, even if it appears to be at varianc...
If the word 'EXAMINATION' is arranged in alphabetical order from the right end, then which of the following letter will be fourth letter to the right of...
Which figure should replace the question mark (?) if the series were to continue?
In each of the following questions, find out which of the answer figures can be formed from the pieces given in the problem figure.
Relevant for Exams:
