Question
Among a set of 6 black balls and 3 white balls, how many
selections of 5 balls can be made such that at least 3 of them are black balls?Solution
Selecting at least 3 black balls from a set of 6 black balls in total selection of 5 balls can be 3 black and 2 white balls 4 black and 1 white balls 5 black and 0 white balls Therefore, our solution expression looks 6C3 × 3C2 + 6C4 × 3C1 + 6C5 × 3C0 = 20 × 3 + 15 × 3 + 6 × 1 = 60 + 45 + 6 = 111 ways
In each of the following questions select the one which is different from the other three responses.
(A) Calm: Windy
(B) Happy: Sane
(C) Extravagant: Thrifty
(D) Limited: Boundless
Select the one which is different from the other three responses.
Who among the following lives on floor number 6?
In each of the following questions select the one which is different from the other three responses.
Four of the following five figures are alike in a certain way and thus form a group. Which is the one that does NOT belong to that group?
Find the odd word/ letters/number pair/number from the given alternatives.
- Out of the following five figures, four are alike in some manner and one differs from these in that manner. Select the odd figure.
Select the one which is different from the other three responses.
