# The weight of 72 books is 9 kg. What is the weight of 40 such books?

**Solution:**

Let's use the concept of the unitary method.

From the given data,

Weight of 72 books = 9 kg

Hence, the weight of 1 book = 9 / 72 = 1 / 8 kg

Therefore, the weight of 40 books = (1 / 8) × 40 = 5 kg

Thus, the weight of 40 books is 5 kg.

NCERT Class 6 Maths Solutions Chapter 12 Exercise 12.3 Question 8

## The weight of 72 books is 9 kg. What is the weight of 40 such books?

**Summary:**

If the weight of 72 books is 9 kg, the weight of 40 such books is 5 kg.