Question
A contractor hires 12 workers to complete a project in
20 days. After 8 days, 4 more workers are employed, and the project is completed 2 days earlier. How many days would it have taken if only 12 workers were employed?Solution
Work done in 8 days by 12 workers = 8 × 12 = 96 units. Remaining work = Total work - 96 = (12 × 20 - 96) = 144 units. New workers = 12 + 4 = 16 workers. Time taken by 16 workers = 144/16 = 9 days. If only 12 workers were employed, time = (96 + 144)/12 = 20 days. Correct answer: c) 20 days
- The average of 36 numbers is 75. If every number is multiplied by 9, what will be the average of the resulting numbers?
The average age of 4 children in a family is 30% of the average age of the mother and the youngest child. The total age of the father and the eldest chi...
A set contains ten numbers. The average of the first six numbers is (x - 4), and the average of the last three numbers is (x + 2). The average of the en...
The average of five even numbers is 68. If we replace two of these even numbers, 84 and 92, with a single even number X, the new average decreases by 4....
The average age of A, B & C is 48 years. Ratio of present ages of A to C is 3:5 and present age of B is 33.33% more than that of A. find the difference...
The average marks of 'm' students in a math test is (m + 5) and the average marks of 30 girls is (2m - 10). If the average marks of all students togethe...
The cost of running a mini train is partly fixed and partly variable. When 50 tickets are sold, the average cost per ticket is Rs. 45. When 70 tickets a...
In a class of 50 students, the girls are 76%. The average weight of boys is 62 kg and that of girls is 58 kg. What is the average weight (in kg) of whol...
Determine the average marks achieved by six additional aspirants if the average score of 24 aspirants in a mock test is 67. Adding the marks of these si...
The average of six numbers is 8. When three new numbers are included in such a way that the first number is  twice the second and second number is thri...
Relevant for Exams:
