Question

The weight of 72 books is 9 kg.

(i) What is the weight of 80 such books?
(ii) How many such books weigh 6 kg?

(please help me)​

Answer 1

Step-by-step explanation:

(I)

$9 \div 72 = 8 \: one \: book \: = 8kg \: \\ \\ 8 \times 80 = 640$

Answer 2

As given 72 books weigh 9kg.

Then find the average weight of a book.

= Total weight/Total books

= 9/72

= 1/8 kg or 0.125 kg

Hence weight of a single book is 0.125kg.

(a) Weight of 80 books = 80 × weight of single book

= 80 × 0.125

= 10 kg

(b) No. of books weighing 6 kg = 6 kg ÷ Weight of single book

= 6 ÷ 0.125

= 48 books.