NCERT Exemplar Problems Solution Class 8 Math Unit 2 Data Handling
(1) (d) Frequency of the class
Sol: According to the basic concept of histogram we know i.e. The heights of the rectangle in the histogram shows the frequency of the class.
(2) (a) Pie chart
Sol: According to the basic concepts, we know i.e. pie chart shows the relationship between a whole and its parts.
(3) (b) 360o
Sol: According to the basic concepts of a circle we know i.e. the central angle of a circle is 360o
(4) (c) 41
Sol: According to the basic concept of range. Highest data-Lowest data = 61 – 20 = 41 range of the given data.
(5) (d) Throwing a stone from a roof of a building.
Sol: Throwing a stone from a roof of a building this experiment is not a random experiment, because it has only one possibility, only one outcome. But random experiment has more than one posibilities.
(6) (b) 1/26
Sol: The total number of alphabets is 26 and we have total 5 vowels. If the probability of choosing 5 vowels from 26 alphabets is 5/26, then the probability of choosing 1 vowel from 26 alphabets is 1/26
(7) (b) 0.4
Sol: According to the given question, 2 out 5 students do not make it to competition, the probability of the students who do not make it to the competition is 2/5 = 0.4
(8) (c) Green
Sol: According to the given pie chart, 1/5 of the votes means = 1/5 x 100% = 20%. Vote, which is received by the green colour.
(9) (c) 24
Sol: According to the given pie chart, ‘others’ colour received 6%. Total students are 400. Then 6/100 x 400 = 24 students voted ‘others’ colour as their favourite.
(10) (d) Number of students liking together yellow and green colour is approximately the same as those for red colour.
(11) (b) 13oc
Sol: Range of data = Highest – Lowest data = 5 – (-8) = 5 + 8 = 13
(12) (d) 1/4
Sol: According to the given information, we have 4 blue buttons. So the probability that the 1 button on the floor is blue = 1/4
Sol: In (iv) no option’s spinner there are total 6 outcomes. In 6 outcomes, red has 2 chances, Blue has 2 Chances and green also has 2 chances. So here, Rahul, Varun and Yash both have same chances to win, the game fairly.
(15) (b) 3/5
Sol: According to the given information the probability of getting a head is = 3/5
(19) (a) 2/5
Sol: According to the given questions, we have total 5 cards. In 5 cards there are 2 cards which have number 2. So the probability of Rohan picking a card that has the number 2 on it is = 2/5.
(20) (d) 2 : 1
Sol: According to the given pie chart. The central angle for parents in muscles is = 1/3 x 360o = 120o and the central angle for proteins in bones is, 1/6 x 360o = 60o. So the ration of distribution of protein in music to that of proteins in the bones is = 120o : 60o = 2 : 1
(21) (d) 96o
Sol: According to the above given pie chart the central angle for proteins in skin is 1/10 x 360o = 36o and the central angle for proteins in bones is, 1/6 x 360o = 60o. So the central angle for proteins in skin and bones together is (36o + 60o) = 96o
(22) (b) 144o
Sol: According to the above given pie chart,
Central angle of protein in muscles = 1/3 x 360o = 120o
Central angle of protein in skin = 1/10 x 360o = 36o
Central angle of protein in bones = 1/6 x 360o = 60o
So, now the central angle of hormones enzymes and other proteins is [360o – (120o + 36o +60o)]
= 360o – 216o
= 144o
(23) (b) 5/12
Sol: According to the given information. After tossing a coin 12 times we get Head 5 times so the chance of occurrence of Head is 5/12.
(24) (d) 12
Sol: According to the given information, the total number of outcomes is (3 + 5 + 4) = 12
(25) (d) Double bar graph
Sol: According to the question, Double bar graph showing two sets of data in same graph.
(26) (c) 25
Sol: The size of class 150 – 175 is, Highest data – Lowest data = 175 – 150 = 25.
(27) (d) 0
Sol: According to the given question, we cannot get number 7 by throwing a dice because the dice have number only 1 to 6.
(28) (d) Pie chart
Sol: As we know i.e. pie chart is also known as circle graph which data represent using circle.
(29) (a) Class Intervals
Sol: As we know i.e. tally graph is used find data quickly. In class, data means class intervals.
(30) (d) 85
Sol: As we know i.e. Upper limit of a class means the upper or highest interval of that class. So here, the upper limit of class 75 – 85 is 85, which is the highest interval of that class.
(31) (c) 3/5
Sol: According to the given question, in 1 to 5 the add numbers are – 1, 3, 5 that means we have 3 add number in 5 numbers. So the probability that the picking slip bears an add number is 3/5.
(32) (b) 3/10
Sol: According to the information, There is total (6 + 5 + 4 + 5) = 20 marbles and we have 6 red marble in 20 marbles. So the probability that the choosen marble is of red coloured is = 6/20 = 3/10.