## Mathematics | Study Mode

Question 1 Mathematics
A
25
B
19
C
18
D
17
Explanation.

Let the three items be M, Y and P.
n{M Y} only = 4-3 = 1
n{M P) only = 5-3 = 2
n{ Y P} only = 2
n{M} only = 12-(1+3+2) = 6
n{Y} only = 10-(1+2+3) = 4
n{P} only = 14-(2+3+2) = 7
n{MPY} = 3
Number of women in the group = 6+4+7+(1+2+2+3) as above =25 women.

Question 2 Mathematics
A
236
B
356
C
526
D
556
Explanation.

Hint: Two methods can be used;
1. Direct division (if you know division in number bases)
2. Convert both sides to base 10, divide and convert your answer back to base 6. Your answer should be 356

Question 3 Mathematics
A
2/3
B
1/2
C
-1/2
D
-2/3
Explanation.

$$a*a^{-1} = aa^{-1} + a + a^{-1} = e$$

if e = 0

$$2.2^{-1} + 2 + 2^{-1} = 0$$

collecting like terms, we have:
$$3.2^{-1} + 2 = 0$$

= $$2^{-1}$$ = -$$\frac{2}{3}$$

Question 4 Mathematics
A
2x2-x+1
B
2x2-x-1
C
2x2+x+1
D
2x2+x-1
Explanation.

No official Explanation yet!

Question 5 Mathematics
A
400 cm2
B
462 cm2
C
66 cm2
D
308 cm2
Explanation.

Total surface area of hemisphere = half of TSA of sphere + circumference of circle

= $$2\pi r^{2} + \pi r^{2} = 3\pi r^{2}$$

= $$3 \times \frac{22}{7} \times 7^{2} = 462cm^{2}$$

Question 6 Mathematics
A
120
B
10
C
20
D
60
Explanation.

To get the answer, we simply do

$$\frac{5!}{(5 - 3)!}$$

= $$\frac{5 \times 4 \times 3 \times 2 \times 1}{2 \times 1}$$

= 60

Question 7 Mathematics
A
49
B
121
C
25
D
64
Explanation.
Mode = 11
Square of the mode = 112
=121

Question 8 Mathematics
A
7.0
B
8.7
C
9.5
D
11.0
Explanation.
Mean ((4*3) + (7*5) + (8*2) + (11*7) + (13*2) + (8*1))/20
(12 + 35 + 16 + 77 + 26 + 8)/20
174/20 = 8.7

Question 9 Mathematics
A
2/3
B
1/2
C
1/3
D
1/4
Explanation.
P(Games ends in draw)
This implies that Team P and Q wins
P(P wins) = 1/2
P(Q wins) = 1/2
P(game ends in a draw) = 1/2*1/2 = 1/4

Question 10 Mathematics
A
7/15
B
2/5
C
1/3
D
1/15
Explanation.
Total number of beads
= 1+2+4+5+3
=15
Number of blue beads = 1
P(Blue beads) = 1/15
Numbers of white beads = 4
P(white beads) = 4/15
P(Blue of white beads)
= P(Blue) + P(White)
= 1/15 + 4/15
= 5/15
= 1/3

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