Question
A man, a woman, a boy, and a girl can complete a certain
task individually in 84 days, 105 days, 140 days, and 210 days respectively. How long will it take for all four of them working together to complete the task?Solution
Let the total work = L.C.M of 84, 105, 140, and 210 = 420 units
Efficiency of a man = 420 ÷ 84 = 5 units/day
Efficiency of a woman = 420 ÷ 105 = 4 units/day
Efficiency of a boy = 420 ÷ 140 = 3 units/day
Efficiency of a girl = 420 ÷ 210 = 2 units/day
So, time taken by a man, a woman, a boy and a girl working together = 420 ÷ (5 + 4 + 3 + 2) = 30 days
‘A’, ‘B’ and ‘C’ started a business by investing Rs. 2500, Rs. 4500 and Rs. 3500, respectively. After 4 months, ‘B’ left and ‘A’ and...
A, B and C started a online education website by investing Rs.28,000, Rs.36,000 and Rs.40,000 respectively. Find the share of A’s, out of an annual pr...
P started a business investing Rs.10000. After 5 months, Q joined her with the capital of Rs.20000. After another 3 months, R joined them with the capit...
A and B started a retail store with initial investments in the ratio 7:8 and their annual profits were in the ratio 3:4. If A invested the money for 9 m...
R and S invested Rs. 1800 and Rs. 2200 respectively. After 6 months, T joined with Rs. 2000. If R’s share in the profit is Rs. 720, find the total pro...
‘P’ and ‘Q’ started a business with investment of Rs. 3,000 and Rs. 4,200, respectively. After 8 months, ‘P’ increased his investment by Rs...
P and Q together started a business with initial investment in the ratio of 1:13, respectively. The time-period of investment for P and Q is in the rati...
P, Q and R enter into a partnership by investing Rs.5000, Rs.8000 and Rs.5600 respectively. After 4 months, P invested Rs.1400 more and Q withdraw the ...
'A' and 'B' invested Rs. 4200 and Rs. 3600 respectively in a business. After 6 months, 'B' reduced his investment by 50%, while 'A' increased his initi...
Aman and Bittu launched a business by investing Rs. 'x' and Rs. 1,500, respectively. Four months later, Chirag joined with an inv...
Relevant for Exams:
