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?
Find the values (s) of k so that the quadratic equation 3x2 - 2kx + 12 = 0 has equal roots.
Given quadratic equation is 3x2 - 2kx + 12 = 0
Here a = 3, b = -2k, c = 12
The quadratic equation will have equal roots if = 0.
b2 - 4ac = 0
Putting the values of a, b and c we get
= ( -2k )2 - 4 (3) (12) = 0
4k 2 - 144 = 0
4k 2 = 144
Therefore, the required values of k are 6 and -6.
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.