Question
Person A and Person B can complete the work alone in 18
days and 24 days, respectively, and the efficiency of Person C is -----% greater than the efficiency of Person A. If Person B starts the work and after 3 days, Persons A and C join in, then the entire work is finished in ---- days. Which of the following options will fit into the blanks provided in the question? A) 10%, 6.4 days B) 15%, 5.2 days C) 20%, 8.3 daysSolution
Answer: D From (A): C = 100/110 * 18 = 180/11 (x + 3)/24 + x/18 + 11x/180 = 1 7.5x + 22.5 + 10x + 11x = 180 28.5x = 157.5 x = 5.5 Required time = 3 + 5.5 = 8.5 days This does not satisfy. From (B): C = 100/115 * 18 = 360/23 (x + 3)/24 + x/18 + 23x/360 = 1 15x + 45 + 20x + 23x = 360 x = 315/58 = 5(25/58) Required time = 3 + 5(25/58) days = 8(25/58) days This does not satisfy. From (C): C = 100/120 * 18 = 15 (x + 3)/24 + x/18 + x/15 = 1 7.5x + 22.5 + 10x + 12x = 180 x = 157.5/29.5 5.3 Required time = 3 + 5.3 = 8.3 days This satisfies.
The ratio of the present ages of father and his son is 9:5. The product of their ages 3 years ago was 33 times of his son’s age that year. What was so...
The present age ratio of Arjun to Virat is 2:z. In 6 years from now, their total ages will be 42 years. Eight years ago, Rahul wa...
If the ratio of the ages of Karan and Saroj is 5 : 7. 8 years ago, the ratio of their ages was 2 : 3. Find the present age of Saroj?
Four years ago, the combined ages of Linda and Joan was 56 years. Four years hence, the ratio of their ages will be 4:5. Find the current age of Linda.
Sum of the present ages of A, B, C and D is 65 years. After 3 years ratio of their ages is 4:3:2:2. What is C’s present age?
The ratio of Rama’s to Shyama’s age is 1 : 2 and the sum of their age 81 years. What will be the ratio of their ages after 7 years?
A’s age is the fourth part of his father’s age. After 8 years, the age of A’s father will be twice the age of B. If B’s 7th birthday is celebrat...
- In a family, the mother is 3 years older than the father and four times as old as the son. If the sum of their present ages is 90 years, how many years lat...
3 years ago, the ratio of the ages of A and B was 2:3 and after 4 years it will become 5:7. Find their present ages.
The ages of A, B and C are in the ratio 6:8:9 and the sum of their ages is 69. Find the ratio of 9 years ago B’s age to C’s age after 9 years.
