MCQs Olympiad IMO Mathematics

Q1. The mean of 20 observations is 12.5. BY error, one observation was noted as -15 instead of 15. Then the correct mean is ___.

1. 11.75
2. 11
3. 14
4. 13

Answer: C

Q2. The median of a given frequency distribution is found graphically with the help of_______.

1. Histogram
2. frequency curve
3. Frequency polygon
4. Ogive

Answer: D

Q3. The average age of 5 teachers is 28 years . If one teacher is excluded the mean gets reduced by2 years. The age of the excluded teacher is_______.

1. 26 years
2. 33 years
3. 36 years
4. 35 years

Answer: C

Q4. The mean of 9 observations is 36. If the mean of the first 5 observations is 32 and that of the last 5 Observations is 39, then the fifth observations is _____.

1. 28
2. 31
3. 43
4. 37

Answer: B

Q5. A bag contains 12 balls of two different colours, out of which x are white. One ball is drawn at random. If 6 more white balls are put in the bag, the probability of drawing a white ball now will be double to that of the previous probability of drawing a white ball. Then, the value of x is ____.

1. 3
2. 4
3. 5
4. 6

Answer: A

Q6. A rectangular carpet has an area of 60 sq. m. Its diagonal and longer side together equal5 times the shorter side. The length of the carpet is ______

1. 5 m
2. 12 m
3. 13 m
4. 14.5 cm

Answer: B

Q7. Walking at three- fourths of his usual speed a man covers a certain distance in two hours more than the time he takes to cover the distance at his usual speed. The time taken by him to cover the distance with his usual speed is ____.

1. 4.5 hours
2. 4.5 hours
3. 6 hours
4. 5 hours

Answer: C

Q8. Six bells commence tolling to gether and toll at intervals of 2,4,6,8,10 and 12 seconds respectively. In 30 minutes, how many times do they toll together ?

1. 4
2. 10
3. 15
4. 16

Answer: D

Q9. A is thrice as good a workman as B and takes 10 days less to do a piece of work than B takes. B can do the work in _____.

1. 12 days
2. 15 days
3. 20 days
4. 30 days

Answer: B

Q10. A train 100 metres long moving at a speed of 50km/hr crosses a train 120 metres long coming from opposite direction in 6 seconds. The speed of second trains is_____.

1. 132 km/hr
2. 82 km/hr
3. 60 km/hr
4. 50km/hr

Answer: B