If 6Pr = 6, find the value of 6Pr+1
30
33
35
15
Correct answer is A
6Pr = 6 Thus r = 1
N.B 6P1 = \(\frac{\text{6!}}{\text{(6 - 1)!}}\)
= \(\frac{\text{6!}}{\text{5!}}\)
= \(\frac{6 \times \text{5!}}{\text{5!}}\) = 6
6Pr + 1 = 6P2 = \(\frac{\text{6!}}{(6 - 2)\text{!}} = \frac{6\text{!}}{\text{4!}}\)
= \(\frac{6 \times 5 \times \text{4!}}{\text{4!}}\)
= 30
2/3
1/2
1/3
1/4
Correct answer is D
P (games end in draw)
=> Team P wins and Q wins
P(P wins) = 1/2
P(Q wins) = 1/2
Therefore P (games ends in draw) = 1/2 x 1/2 = 1/4
7.0
8.7
9.5
11.0
Correct answer is B
Mean = ∑fx/∑f
Mean = (4x3) + (7x5) + ... + (8x1) all divided by 20
Mean = 174/20 = 8.7
49
121
25
64
Correct answer is B
Mode = score with highest frequency = 11.
Square of 11 = 121
Find the dimensions of a rectangle of greatest area which has a fixed perimeter p.
square of sides p
square of sides 2p
square of sides (p/2)
square of sides (p/4)
Correct answer is D
Let the rectangle be a square of sides p/4.
So that perimeter of square = 4p
4 x (p/4) = p.