2009 - JAMB Mathematics Past Questions and Answers - page 5
41
| No. of Days | 1 | 2 | 3 | 4 | 5 | 6 |
| No. of students | 20 | 2x | 60 | 40 | x | 50 |
The distribution above shows the number of days a group of 260 students were absent from school in a particular term. How many students were absent for t least four days in the term
A
180
B
120
C
110
D
40
correct option: b
20 + 2x + 60 + 40 + x + 50 = 250
170 + 3x = 260
3x = 260 - 170
3x = 90
x = 90/3 = 30
At least 4 days
4 days = 40
5 days = 30
6 days = 50
Total = 120
Users' Answers & Comments42
A
45
B
50
C
60
D
75
correct option: b
Sectorial angle of apple
100 + 100 + 115 + x = 30o
315 + x = 360
x = 360 - 315
x = 45o
360o represents 400
1o represents 400 / 360
45o represents (400/360) x (45/1)
= 50 apples
Users' Answers & Comments43
The probability of a student passing any examination is 2/3. If the students takes three examination, what is the probability that he will not pass any of them
A
2/3
B
4/9
C
8/27
D
1/27
correct option: d
P(pass) = 2/3
P(not pass) = 1 - 2/3 = 1/3
P(not passing any of the 3 Exams) = 1/3 x 1/3 x 1/3
= 1/27
Users' Answers & Comments44
5, 8, 6 and k occur with frequency 3, 2, 4, and 1 respectively an d have a mean of 5.7. Find the value of k
A
4
B
3
C
2
D
1
correct option: c
| x | f | fx | |
| 5 | 3 | 15 | |
| 8 | 2 | 16 | |
| 6 | 4 | 24 | |
| k | i | k | |
| ∑f=10 | ∑fx=55+k |
| Mean = | ∑fx |
| ∑fx |
| 5.7 = | 55+k |
| 10 |
57 = 55 + k
k = 57 - 55
k = 2
Users' Answers & Comments45
What is the mean deviation of x, 2x, x+1 and 3x. If their mean is 2?
A
0.5
B
1.0
C
1.5
D
2.0
correct option: a
| x | ∴x | x-X | /x-X/ |
| x | 1 | -1 | 1 |
| 2x | 2 | 0 | 0 |
| x+1 | 2 | 0 | 0 |
| 3x | 3 | 1 | 1 |
| ∑/x-X/=2 |
| Mean = | x+2x+x+1+3x |
| ____4 |
| 2 = | 7x+1 |
| _4 |
8 = 7x+1
7x = 8-1
7x = 7
x = 1
| Mean deviation = | ∑/x-X/ |
| __n |
| = | 2 |
| 4 |
| = | 1 |
| 2 |
= 0.5
Users' Answers & Comments46
In how many ways can a delegation of 3 be chosen from 5 men and 3 women. If at least 1 man and 1 woman must be included?
A
15
B
28
C
30
D
45
correct option: d
Users' Answers & Comments47
In how many ways can 9 people be seated if 3 chairs are available
A
720
B
504
C
336
D
210
48
| Marks | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |
| No. of students | 3 | 4 | 1 | 0 | 4 | 5 | 2 | 1 |
The table above shows the distribution of marks of students in a test. Find the probability of passing the test if the pas mark is 5
A
| 3 |
| 5 |
B
| 2 |
| 5 |
C
| 7 |
| 20 |
D
| 1 |
| 5 |
correct option: a
Total number of students = 20
| Marks | No. of students |
| 5 | 0 |
| 6 | 4 |
| 7 | 5 |
| 8 | 2 |
| 9 | 1 |
| 12 |
| P(passing)= | 12 |
| 20 |
| = | 3 |
| 5 |
49
Subtract 164189 from 186309
A
11219
B
21129
C
21139
D
22119
correct option: d
You borrow 1 which transforms to 9, because of it's base
1863099
-164189
________
22119
Users' Answers & Comments
50
If 55x + 52x = 7710, find x.
A
5
B
6
C
7
D
10
correct option: c
5 x X1 + 5 x XO + 5 x X1 + 2 x XO = 77
5X + 5 + 5X + 2 = 77
10X + 7 = 77
10X = 77 - 7
10X = 70
X = (\frac{70}{10})
= 7
Users' Answers & Comments