7. The weight of 56 books is 8 kg.
(i) What is the weight of 154 such books?
(ii) How many such books weigh 5 kg?
Answers
Answer:
(i) Weight of 154 books = 22 kg.
And
(ii) 5 kg is weight of 35 books.
Step-by-step explanation:
Given,
Weight of 56 books = 8 kg
According to the question
(i)
Weight of 56 books = 8 kg
Weight of 1 book = 8/56 kg
Weight of 154 books = 8/56 × 154 kg
Weight of 154 books = (8 × 154)/56 kg
Weight of 154 books = 1232 / 56 kg
Weight of 154 books = 22 kg
(ii)
8 kg is the weight of 56 books
1 kg is the weight of 56/8 books
1 kg is the weight of 7 books
5 kg is weight of 5 × 7 books
5 kg is weight of 35 books.
Hence,
(i) Weight of 154 books = 22 kg.
And
(ii) 5 kg is weight of 35 books.
If a set of 56 books weighs 8000 grams, you can get average weight of a book, which is
8000
56
=
142.86
grams.
Now you can compute weights of 152 books
=
152
⋅
142.86
=
21715
grams or approximately 21.7 kg.
If you want to buy 5 kg book, you need to get
5000
142.85
=
35
books. In other words, 35 books weigh 5 kg (or 5000 grams).