A takes 6 days less than B to do a work. If both A and B working together can do it in 4 days, how many days will B take to finish it?
Suppose B alone takes x days to to finish the work.
Then, A alone can finish it in (x-6) days.
(A's one days work) + (B's one day work) =
And, ( A+B)'s one day's work =
But, x cannot be less than 6.
So, x = 12
Hence, B alone can finish the work in 12 days.
A shopkeeper buys some books for Rs. 80. If he had bought 4 more books for the same amount, each book would have cost Rs. 1 less. Find the number of books he bought.
OR
The sum of two number is 9 and the sum of their reciprocals is . Find the numbers.