Skip to main content

f A alone can do a piece of work in 8 days and B alone can do the same work in 12 days. How many days A and B required to finish the same work if they work togather?

If A alone can do a piece of work in 8 days and B alone can do the same work in 12 days. How many days A and B required to finish the same work if they work togather?

A. 24/5 days
B. 24 days
C. 5day days
D. 5/24 days
E. None of these

 Option A

 Explanation:
A alone one day work = 1/8
B alone one day work = 1/12
Both A and B one day work = (1/8 + 1/12) = (3/24 + 2/24)
= 5/24
so A and B together finish the work in 24/5 day 
or 4 4/5 days.

Comments

Post a Comment

Popular posts from this blog

It takes 10 days for digging a trench of 100 m long, 50 m broad and 10 m deep. What length of trench, 25 m broad and 15 m deep can be dug in 30 days ?

 It takes 10 days for digging a trench of 100 m long, 50 m broad and 10 m deep.  What length of trench, 25 m broad and 15 m deep can be dug in 30 days ?       a) 400 m          b) 200 m          c) 100 m          d) 89m Expl : More days, more length (Direct)       Less breadth, more length (Indirect)       More depth, less length (Indirect       Days      10 : 30;       Breadth  25 : 50;                  : : 100 : x       Depth    15 : 10;                     :. 10 * 25* 15 * x = 30 *50 * 10 *100             x= (30*50*10*100)/10*25*15 = 400      So the required length = 400m
Post a Comment
Read more

Find the number of perfect squares in the given series 2013, 2020, 2027,.

Find the number of perfect squares in the given series 2013, 2020, 2027,................, 2300   (Hint 44^2=1936) a. 1   b. 2    c. 3   d. Can’t be determined Answer: a Explanation: The given series is an AP with common difference of 7. So the terms in the above series are in the form of 2013 + 7k.  We have to find the perfect squares in this format in the given series. Given that 44^2 = 1936. Shortcut: To find the next perfect square, add 45th odd number to 44^2. So 45^2 = 1936 + (2 x 45 -1) = 2025 46^2 = 2025 + (2 x 46 - 1) = 2116 47^2 = 2116 + (2 x 47 - 1) = 2209 Now subtract 2013 from the above numbers and divide by 7. Only 2209 is in the format of 2013 + 7k.  One number satisfies.
Post a Comment
Read more