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Which of the following is not true? (a) rational numbers are closed under addition. (b) rational numbers are closed under subtraction. (c) rational numbers are closed under multiplication. (d) rational numbers are closed under division.

The correct answer is (d) rational numbers are closed under division. Explanation According to the properties of rational numbers: Rational... View Article

The numerical expression (3/8) + (-5/7) = (-19/56) shows that (a) rational numbers are closed under addition. (b) rational numbers are not closed under addition. (c) rational numbers are closed under multiplication. (d) addition of rational numbers is not commutative.

The correct answer is (a) rational numbers are closed under addition. Explanation (3/8) + (-5/7) On taking the LCM of the denominators of... View Article

A number of the form p/q is said to be a rational number if (a) p and q are integers. (b) p and q are integers and q ≠ 0 (c) p and q are integers and p ≠ 0 (d) p and q are integers and p ≠ 0 also q ≠ 0

The correct answer is (b) p and q are integers and q ≠ 0 Explanation A rational number is a number that is in the form of p/q, where p... View Article

A number which can be expressed as p/q where p and q are integers and q≠0 is (a) natural number. (b) whole number. (c) integer. (d) rational number

The correct answer is (d) rational number Explanation A rational number is a number that is in the form of p/q, where p and q are... View Article

The lengths of 62 leaves of a plant are measured in millimetres and the data is represented in the following table. Draw a histogram to represent the data above.

Length (in mm) Number of leaves 118-126 8 127-135 10 136-144 12 145-153 17 154-162 7... View Article

Draw a histogram to represent the following grouped frequency distribution.

Age (in years) Number of teachers 20-24 10 25-29 28 30-34 32 35-39 48 40-44 50 45-49... View Article

Draw a histogram of the following distribution.

Height (in cm) Number of students 150-153 7 153-156 8 156-159 14 159-162 10 162-165 6 165-168 5 Solution The bar graph of... View Article

The following are the marks (out of 100) of 60 students in mathematics. 16, 13, 5, 80, 86, 7, 51, 48, 24, 56, 70, 19, 61, 17, 16, 36, 34, 42, 34, 35, 72, 55, 75, 31, 52, 28,72, 97, 74, 45, 62, 68, 86, 35, 85, 36, 81, 75, 55, 26, 95, 31, 7, 78, 92, 62, 52, 56, 15, 63,25, 36, 54, 44, 47, 27, 72, 17, 4, 30. Construct a grouped frequency distribution table with width 10 of each class starting from 0 – 9.

Solution Arranging the given data in ascending order 4, 5, 7, 7,13,15,16,16,17,17,19, 24, 25, 26, 27, 28, 30, 31,31,34, 34, 35, 35, 36, 36, 36,... View Article

Obtain the mean of the following distribution.

Frequency Variable 4 4 8 6 14 8 11 10 3 12 Solution xi fi xifi 4 4 16 6 8 48... View Article

If the mean of the following data is 20.2, find the value of p:

x 10 15 20 25 30 f 6 8 p 10 6 Solution According to the given details Mean = 20.2 We know that mean can be represented as =20.2 Hence... View Article

Expenditure on Education of a country during a five year period (2002-2006), in crores of rupees, is given below. Represent the information above by a bar graph.

Education Expenditure Elementary education 240 Secondary education 120 University education 190 Teacher's... View Article

he expenditure of a family on different heads in a month is given below. Draw a bar graph to represent the data above.

Head Food Education Clothing House Rent Others Saving Exenditure 4000 2500 1000 3500 2500 1500 Solution The... View Article

Convert the given frequency distribution into a continuous grouped frequency distribution. In which intervals would 153.5 and 157.5 be included?

Class interval Frequency 150-153 7 154-157 7 158-161 15 162-165 10 166-169 5 170-173 6... View Article

Prepare a continuous grouped frequency distribution from the following data. Also find the size of class intervals.

Mid point Frequency 5 4 15 8 25 13 35 12 45 6 Solution Let m be the mid-point of a class... View Article

The scores (out of 100) obtained by 33 students in a mathematics test are as follows: 69, 48, 84, 58, 48, 73, 83, 48, 66, 58, 84 000 66, 64, 71, 64, 66, 69, 66, 83, 66, 69, 71 81, 71, 73, 69, 66, 66, 64, 58, 64, 69, 69 Represent this data in the form of a frequency distribution.

Solution A frequency distribution is a representation, either in a graphical or tabular format, that displays the number of observations within... View Article

The value of π upto 35 decimal places is given below: 3. 14159265358979323846264338327950288 Make a frequency distribution of the digits 0 to 9 after the decimal point.

Solution A frequency distribution is a representation, either in a graphical or tabular format, that displays the number of observations within... View Article

The blood groups of 30 students are recorded as follows: A, B, O, A, AB, O, A, O, B, A, O, B, A, AB, B, A, AB, B, A, A, O, A, AB, B, A, O, B, A, B, A Prepare a frequency distribution table for the data.

Solution A frequency distribution is a representation, either in a graphical or tabular format, that displays the number of observations within a... View Article

Is it correct to say that in a histogram, the area of each rectangle is proportional to the class size of the corresponding class interval? If not, correct the statement.

Solution The given statement is incorrect. In a histogram, the area of each rectangle is proportional to the corresponding frequency of its... View Article

A football player scored the following number of goals in the 10 matches: 1, 3, 2, 5, 8, 6, 1, 4, 7, 9 Since the number of matches is 10 (an even number), therefore, the median = (5th observation + 6th observation)/2 = (8 + 6)/2 = 7 Is it the correct answer and why?

Solution No. The obtained data solution in the question incorrect answer, because the data has to be ordered in either ascending or descending... View Article

A child says that the median of 3, 14, 18, 20, 5 is 18. What doesn’t the child understand about finding the median?

Solution The child says that the median of 3, 14, 18, 20, 5 is 18. From this we understand that the child doesn’t understand... View Article