Question
If Arjun can complete his work in 28 days by working 4
hours a day, how many hours a day should he work to finish the same work in 16 days?Solution
ATQ,
Let the efficiency of Arjun be 'x' units per hour
Therefore, total work = 4 × 28 × x = 112x units
Let the time he should work to complete the work in 16 days be 'y' hours a day.
ATQ;
112x = 16 × y × x
Or, y = 7
Therefore, he should work for 7 hours a day.
Alternate solution:
Required time = (4 × 28) ÷ 16 = 7 hours
The ratio of the number of girls to the number of boys in a school of 720 students is 3 : 5. If 18 boys left the school, find how many new girls ...
Two containers have mixtures of milk and water, respectively, in the ratio 3:2 and 6:5 in what ratio should the contents be mixed so that the ratio of m...
Rs. 11200 was divided among A, B and C in the ratio 2:3:3. B kept Rs. 1000 for himself, gave Rs. 600 to his mother and divided the remaining money among...
The ratio of the number of English books to Hindi books in a library shelf is 4:3. If 90 Hindi books are written by Pradeep, which constitutes 30% of th...
A total amount of Rs. 1220 is to be divided between two friends, Ram and Ranjan, in the ratio (7/9):(11/12). What is the difference between the amounts ...
The ratio of P’s to Q’s salary is 5 : 7. If Q’s salary is increased by 35%, his total salary becomes Rs. 52,920. What is the salary of P?
...The ratio of males and females in a zoo is 5:6 respectively and the percentage of children among males and the percentage of children among females are ...
Divide Rs. 2541 among Deepa and Deepak in the ratio (11/8) : (11/6) ?
Two years ago the ratio of annual salary of three friends P, Q and R is 4 : 3 : 5. Every year since then the salary of P, Q and R increases by 10%, 12% ...
The ratio of zinc and copper in a brass pieces is 3:4. How much zinc will be there in 140 kg of such a piece?