In a cricket match, a bats woman hits a boundary 6 times out of 30 balls she plays. Find the probability that she did not hit a boundary. Solution: Total number of blls played by the batswoman = 30 Boundaries hit = 6 No. of balls in which she did not hit any numbers =… Continue reading Probability – Exercise 15.1 – Class IX

# Tag: NCERT class 9 mathematics

## Statistics – Exercise 14.4 – Class IX

EXERCISE 14.4 The following number of goals was scored by a team in a series of 10 matches: 2, 3, 4, 5, 0, 1, 3, 3, 4, 3 Find the mean, median and mode of these scores. Solution: The number of goals scored by the team is 2, 3, 4, 5, 0, 1, 3,… Continue reading Statistics – Exercise 14.4 – Class IX

## Statistics – Exercise 14.3 – Class IX

A survey conducted by an organisation for the cause of illness and death among the women between the ages 15 - 44 (in years) worldwide, found the following figures (in %): Sl. No. Causes Female Fertility Rate(%) 1 Reproductive health conditions 31.8 2 Neuropsychiatric conditions 25.4 3 Injuries 12.4 4 Cardiovascular conditions 4.3 5 Respiratory… Continue reading Statistics – Exercise 14.3 – Class IX

## Statistics – Exercise 14.2 – Class IX

The blood groups of 30 students of Class VIII are recorded as follows: A, B, O, O, AB, O, A, O, B, A, O, B, A, O, O, A, AB, O, A, A, O, O, AB, B, A, O, B, A, B, O. Represent this data in the form of a frequency distribution table. Which… Continue reading Statistics – Exercise 14.2 – Class IX

## Statistics – Exercise 14.1 – Class IX

Give five examples of data that you can collect from your day-to-day life. Solution: Number of coconut plants in our locality. Temperature of summer in the last 10 years in Hyderabad. Marks about by our class students in mathematics subject. Population of India in last 10 decades. Number of males per 1000 females in India.… Continue reading Statistics – Exercise 14.1 – Class IX

## Surface Area and Volumes – Exercise 13.7 – Class IX

Assume π = 22/7 , unless stated otherwise. Find the volume of the right circular cone with (i) radius 6 cm, height 7 cm (ii) radius 3.5 cm, height 12 cm Solution: (i) r = 6 cm; h = 7cm Volume of the cone = 1/3πr2h = 1/3 x 22/7 x 62 x 7 =… Continue reading Surface Area and Volumes – Exercise 13.7 – Class IX

## Surface Area and Volumes – Exercise 13.8 – Class IX

Assume π = 22/7 , unless stated otherwise. Find the volume of a sphere whose radius is (i) 7 cm (ii) 0.63 m Solution: (i) Volume of sphere = 4/3 πr3 = 22/7 x 4/3 x 73 = 1437.33 m3 (ii) Volume of sphere = 4/3 πr3 = 22/7 x 4/3 x (0.63)3 = 1.05m3… Continue reading Surface Area and Volumes – Exercise 13.8 – Class IX

## Surface Area and Volumes – Exercise 13.6 – Class IX

Assume π = 22/7 , unless stated otherwise. The circumference of the base of a cylindrical vessel is 132 cm and its height is 25 cm. How many litres of water can it hold? (1000 cm3 = 1l) Solution: The circumference of the base of a cylindrical vessel = 132 cm = 2πr ; h… Continue reading Surface Area and Volumes – Exercise 13.6 – Class IX

## Surface Area and Volumes – Exercise 13.5 – Class IX

A matchbox measures 4 cm × 2.5 cm × 1.5 cm. What will be the volume of a packet containing 12 such boxes? Solution: Volume of 1 match box = lbh [here, l = 4cm , b = 2.5cm, h = 1.5cm] = 4 x 2.5 x 1.5 = 15 cm3 Volume of 12 such… Continue reading Surface Area and Volumes – Exercise 13.5 – Class IX

## Surface Area and Volumes – Exercise 13.4 – Class IX

Assume π = 22/7 , unless stated otherwise. Find the surface area of a sphere of radius: (i) 10.5 cm (ii) 5.6 cm (iii) 14 cm Solution: (i) r = 10.5 cm Surface area of the sphere = 4πr2 = 4 x 22/7 x (10.5)2 = 1386 cm2 (ii) r = 5.6 cm Surface area… Continue reading Surface Area and Volumes – Exercise 13.4 – Class IX