Pipes & Cisterns Mcqs

Q.  Two pipes can fill a tank in 18 minutes and 15 minutes. An outlet pipe can empty the tank in 45 minutes. If all the pipes are opened when the tank is empty, then how many minutes will it take to fill the tank?

a. 12
b. 13
c. 11
d. 10


ANSWER: See Answer
 
Part of the filled by all the three pipes in one minute

= 1/18 + 1/15 – 1/45 = (5 + 6 – 2)/90 = 9/90 = 1/10
So, the tank becomes full in 10 minutes.
MCQs:  Two pipes A and B can fill a cistern in 20 and 30 minutes respectively, and a third pipe C can empty it in 40 minutes. How long will it take to fill the cistern if all the three are opened at the same time?
Category: Mathematics Quizzes,   Published by: T-Code Scripts
MCQs:  A question paper consists of five problems, each problem having three internal choices. In how many ways can a candidate attempt one or more problems?
Category: Mathematics Quizzes,   Published by: T-Code Scripts
MCQs:  In a class there are 20 boys and 25 girls. In how many ways can a boy and a girl be selected?
Category: Mathematics Quizzes,   Published by: T-Code Scripts
MCQs:  In how many ways can three consonants and two vowels be selected from the letters of the word “TRIANGLE”?
Category: Mathematics Quizzes,   Published by: T-Code Scripts
MCQs:  A bag contains nine yellow balls, three white balls and four red balls. In how many ways can two balls be drawn from the bag?
Category: Mathematics Quizzes,   Published by: T-Code Scripts
MCQs:  How many four digit even numbers can be formed using the digits {2, 3, 5, 1, 7, 9}
Category: Mathematics Quizzes,   Published by: T-Code Scripts
MCQs:  How many four digit numbers can be formed using the digits {1, 3, 4, 5, 7,9}(repetition of digits is not allowed)?
Category: Mathematics Quizzes,   Published by: T-Code Scripts
MCQs:  The number of ways in which six boys and six girls can be seated in a row for a photograph so that no two girls sit together is_________?
Category: Mathematics Quizzes,   Published by: T-Code Scripts
MCQs:  A letter lock consists of three rings each marked with six different letters. The number of distinct unsuccessful attempts to open the lock is at the most__________?
Category: Mathematics Quizzes,   Published by: T-Code Scripts
MCQs:  A committee has 5 men and 6 women. What are the number of ways of selecting a group of eight persons?
Category: Mathematics Quizzes,   Published by: T-Code Scripts
MCQs:  What are the number of ways to select 3 men and 2 women such that one man and one woman are always selected?
Category: Mathematics Quizzes,   Published by: T-Code Scripts
MCQs:  A committee has 5 men and 6 women. What are the number of ways of selecting 2 men and 3 women from the given committee?
Category: Mathematics Quizzes,   Published by: T-Code Scripts
MCQs:  The number of arrangements that can be made with the letters of the word MEADOWS so that the vowels occupy the even places?
Category: Mathematics Quizzes,   Published by: T-Code Scripts
MCQs:  Using all the letters of the word “NOKIA”, how many words can be formed, which begin with N and end with A?
Category: Mathematics Quizzes,   Published by: T-Code Scripts
MCQs:  Using all the letters of the word “THURSDAY”, how many different words can be formed?
Category: Mathematics Quizzes,   Published by: T-Code Scripts
MCQs:  How many three letter words are formed using the letters of the word TIME?
Category: Mathematics Quizzes,   Published by: T-Code Scripts
MCQs:  A boy has nine trousers and 12 shirts. In how many different ways can he select a trouser and a shirt?
Category: Mathematics Quizzes,   Published by: T-Code Scripts
MCQs:  There are 30 people in a group. If all shake hands with one another , how many handshakes are possible?
Category: Mathematics Quizzes,   Published by: T-Code Scripts
MCQs:  In how many different ways can the letters of the word ‘OPTICAL’ be arranged so that the vowels always come together?
Category: Mathematics Quizzes,   Published by: T-Code Scripts
MCQs:  In how many different ways can the letters of the word ‘MATHEMATICS’ be arranged so that the vowels always come together?
Category: Mathematics Quizzes,   Published by: T-Code Scripts