Test Index

UPTET Paper 2 Math and Science Model Test 5

Section: Mathematics and Science

Question : 146 of 150

Marks: +1, -0

Find the average of square from 1 to 9.

Solution:

Concept:

Sum of squares of first n natural numbers is given by

\frac{n(n+1)(2n+1)}{6}

Average = sum divided by count.

Explanation:

Here n = 9.

Sum of squares =

\frac{9 \times (9+1) \times (2 \times 9 + 1)}{6}

\frac{9 \times 10 \times 19}{6} = \frac{1710}{6} = 285

Number of terms = 9.

Average =

\frac{285}{9} = 31.666... \approx 31.67

Answer:

Option A: 31.67

Go to Question:

Prev Question

Next Question