Allied & ICAR Exam Bank • ALLIED_1831MCQ • 2 Marks
Section 8: General Aptitude
Quantitative Aptitude
Subtopic: Numerical Computation
Question Statement:
Three pipes P, Q, and R can fill a chemical tank in 12, 15, and 20 hours respectively. If pipe P is kept open constantly and pipes Q and R are opened alternately for one hour each starting with Q, how many hours will it take to fill the tank?
Options:
(A) 7 hours
(B) 6.5 hours
(C) 8 hours
(D) 7.5 hours
Answer Key:
A
Step-by-Step Solution & Explanation
Total capacity = 60 units. P = 5, Q = 4, R = 3. Hr 1: P+Q = 9. Hr 2: P+R = 8. In 2 hrs: 17 units. In 6 hrs: 51 units. Remaining = 9 units, filled by P+Q in 7th hr. Total time = 7 hours.