Question

11. The weight of 56 books is 7 kg.
(a) What is the weight of 90 such books?
(b) How many such books weigh 7.5 Kg?

Answer 1

Step-by-step explanation:

Weight of 56 books is 7 kg ( ie 7000 g).

Therefore, weight of a single book will be:

(7000/56) g = 125 g

Thus, 56 books each of 125 g weight collectively weighs 7000 g or 7 kg.

The weight of 90 books will be:

(125 * 90) g = 11250 g or 11.25 kg

Let the number of books weighing 7.5 kg be ‘x'. Then x multiplied by 125 equals 7500.

(x * 125) g = 7500 g

Therefore x = 7500 / 125 books

Hence, x = 60 books. Thus, 60 books each weighing 125 g all together weighs 7.5 kg.

Hope it helps!