NCERT Exemplar Solutions
Class 6 - Mathematics - Unit 1: Number System - Multiple Choice Questions
Question 24

Question.  24

Number of even numbers between 58 and 80 is

(A)

10

(B)

11

(C)

12

(D)

13

Detailed Answer with Explanation:

Step 1:Even numbers” are numbers divisible by 2 (like 2, 4, 6, ...).

Step 2: “Between 58 and 80” means greater than 58 and less than 80.

Step 3: The first even number after 58 is 60.
The last even number before 80 is 78.

Step 4: List them to see the pattern:
60, 62, 64, 66, 68, 70, 72, 74, 76, 78

Step 5 (count using a formula):

First term \(a = 60\)

Last term \(l = 78\)

Common difference \(d = 2\)

Number of terms \(n\) is

\[ n = \dfrac{l - a}{d} + 1 \]

\[ n = \dfrac{78 - 60}{2} + 1 \]

\[ n = \dfrac{18}{2} + 1 \]

\[ n = 9 + 1 = 10 \]

Answer: 10 (Option A)

NCERT Exemplar Solutions Class 6 – Mathematics – Unit 1: Number System – Multiple Choice Questions | Detailed Answers