Question
It takes "Aditi" 12 days alone herself to complete a
task. The differences in efficiency between "Beena" and "Aditi" are 20% and 25%, respectively. "Aditi" and "Beena" begin working together, but 3 days in, "Aditi" leaves. Calculate how long it took "Beena" and "Chinky" working together to complete the remaining tasks.Solution
ATQ, When work is constant, ratio of efficiency is inverse of ratio of time taken. So, ratio of efficiency of 'Aditi' and 'Beena' = 5:6 So, ratio of time taken by 'Aditi' and 'Beena' to finish the work = 6:5 Time taken by 'Beena' alone to finish the work = 12 × (5/6) = 10 days And ratio of efficiency of 'Beena' and 'Chinky' = 4:5 So, ratio of time taken by 'Beena' and 'Chinky' to finish the work = 5:4 Time taken by 'Chinky' alone to finish the work = 10 × (4/5) = 8 days Let, the total work be 120 units {LCM of (8, 10 and 12) } So, efficiency of 'Aditi' = (120/12) = 10 units/day Efficiency of 'Beena' = (120/10) = 12 units/day Efficiency of 'Chinky' = (120/8) = 15 units/day Work done by 'Aditi' and 'Beena' together in 3 days = (10 + 12) × 3 = 66 units Remaining work = 120 - 66 = 54 units So, the time taken by 'Beena' and 'Chinky' together to finish the remaining work = {54/(12 + 15) } = (54/27) = 2 days
In a mayoral election between two nominees, 20% of the total votes were rejected as invalid. Out of the valid votes, 65% went to the winning candidate, ...
Monthly income of A is Rs. 55000 out of which he spent 21%, 9% and 22% of his total income in rent, medicine and transportation, respectively. Find his ...
If the population of a city increases by 20% every year and is expected to be 43,200 after 2 years, then what is its present population?
A person 'P' allocates 25% of his monthly salary towards rent. Out of the remaining salary, he spends 40% on food and clothing, saving the rest. His tot...
The population of a village two years ago was 'X'. Over the next two years, the population increased by 30% in the first year and...
Income of A is twice the income of B. B and A spend 65% and 75% respectively of their incomes. Find the savings of A, if B saves Rs. 7000 in a month.
A person saves 30% of his monthly income. If his monthly is increased by 45% and he still saves the same amount as before then find percentage increase ...
A number is first increased by 55%, and then decreased by 35%. What is the net percentage change in the original number?
If 45% of a number is 90, what is 60% of the same number?
In village P, the number of male voters is 45% more than the number of female voters. The ratio of male voters in village P to village Q is 8:5. If the ...
