In this article you will get CBSE Class 10 Mathematics: Important 1 Mark Questions to be prepared for Section-A of paper for Board Exam 2020. All the questions are completely solved to help you make an easy and quick preparation.
Given below are some sample questions from the set of CBSE Class 10 Mathematics: Important 1 Mark Questions:
Q. If the HCF of 65 and 117 is expressible in the form of 65 m – 117, then find the value of m.
Sol.
We have, 65 = 13 × 5
And 117 = 13 × 9
Hence, HCF = 13
According to question 65m – 117 = 13
⇒ 65m = 13 + 117 = 130
⇒ m = 130/65 = 2
Q. If the common difference of an A.P. is 3, then find a20 – a15.
Sol.
Let the first term of the AP be a.
an = a(n − 1)d
a20 – a15 = [a + (20 – 1)d] – [a + (15 – 1)d]
= 19d – 14d
= 5d
= 5 × 3
Q. Find the value of a so that the point (3, a) lies on the line represented by 2x – 3y = 5.
Sol.
Since point (3, a) lies on line 2x – 3y = 5.
Then, 2 x 3 – 3 x a = 5
⟹ 6 – 5 = 3a
⟹ a = 1/3
Q. For what value of k will k + 9, 2 k ‒ 1 and 2k + 7 are the consecutive terms of an A.P.?
Sol.
If three terms x, y and z are in A.P. then, 2 y = x + z
Since k + 9, 2 k ‒ 1 and 2 k + 7 are in A.P.
∴ 2(2k − 1) = (k + 9) + (2k + 7)
⟹ 4k – 2 = 3k + 16
⟹ k = 18
Q. Find the median using an empirical relation, when it is given that mode and mean are 8 and 9 respectively.
Sol.
The relation between Mean, Median and Mode of the given data is:
Mode = 3Median − 2Mean
⟹ 8 = 3Median − 2 × 9
⟹ 3Median = 8 + 18
⟹ Median = 26/3
⟹ Median = 8.67