## Mathematics | Study Mode

Question 1
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
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)

Question 3
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
A
2x2-x+1
B
2x2-x-1
C
2x2+x+1
D
2x2+x-1
Explanation.

No official Explanation yet!

Question 5
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
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
A
49
B
121
C
25
D
64
Explanation.
Mode = 11
Square of the mode = 112
=121

Question 8
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
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
A
7/15
B
2/5
C
1/3
D
1/15
Explanation.
= 1+2+4+5+3
=15
Number of blue beads = 1