Start learning 50% faster. Sign in now
Let number of white ribbons in the box is ‘x’. Number of green ribbons in the box = (21 – x) According to question, [x × (21 – x)]/ 21C2 = 18/35 x (21 – x)/210 = 18/35 x (21 – x) = 18 × 6 x2 – 21x + 108 = 0 x = 12 or x = 9 So, the box contains either 12 white ribbons and 9 green ribbons or 9 white ribbons and 12 green ribbons. Now, if ‘B’ green ribbons are added and probability of drawing a green ribbon from the box becomes 1/2, it means number of green ribbons was less than number of white ribbons in the box initially. So, the numbers of white and green ribbons in the box initially were 12 and 9 respectively. Therefore, [A] = 12 and [B] = 3. Let number of yellow ribbons added in the box be ‘z’. So, [z/ (21 + 3 + z)] = 1/5 5z = z + 24 4z = 24 z = 6 So, [C] = 6 Required difference = 6-3 = 3
Find the odd one out
In the following question, select the odd word from the given alternatives.
Out of the given options, three are similar in a certain manner. However, one option is NOT like the other three. Select the option which is different f...
Four number-pairs have been given, out of which, three are alike in some manner and one is different. Select the number-pair that is different.
The second number in the given number-pairs is obtained by performing certain mathematical operation(s) on the first number. The same operation(s) is/ar...
Four pairs of numbers have been given, out of which three are alike in some manner, while one is different. Choose out the odd one.
Odd one out
Find the odd set of numbers from the given alternatives?
Four number-pairs have been given, out of which three are alike in some manner and one is different. Select the number-pair that is different.
Odd one out: