Question
Person A is twice as efficient as Person B. Person B can
complete a certain task in 32 days, while Person C takes 4 days more than Person A to finish the same task. Which of the following could be the number of days they work together such that the task remains incomplete?Solution
According to the question,
Time taken by ‘A’ to complete the work = 32/2 = 16 days
Time taken by ‘C’ to complete the work = 16 + 4 = 20 days
Let the total work = 160 units
Efficiency of ‘A’ = 160/16 = 10 units/day
Efficiency of ‘B’ = 160/32 = 5 units/day
Efficiency of ‘C’ = 160/20 = 8 units/day
When they work together for 7 days, work done = (10 + 5 + 8) × 7 = 161 units
Therefore, maximum number of days they can work together such that the work doesn’t get completed is 6 days.
Which of the following methods to measure seasonal variations comparatively utilizes the given data less?
If Q₁, Q₂ and Q₃ are three quartiles of a frequency distribution, which of the following holds if the distribution is negatively skewed?
...A systematic sample does not yield good result, if -
At the centre multipurpose socio-economic surveys are mainly conducted by -
The main aim of agricultural census is -
For discrete distribution, the co-efficient of kurtosis β₂ is -
For the given 6 values 15, 24, 18, 33, 42, 54, the three yearly moving averages are -
byx and bxy are two regression coefficients. If byx > 0, then bxy will be -
The variance of first n natural numbers is -
Which of the following is not true for geometric mean?