108 identical books have a mass of 30 kg. Find(i) the mass of 150 such books,(ii) the number of such books that have a massof 20 kg.
Accepted Solution
A:
Answer:The mass of 150 books = 41.7kgThe number of books that have mass 20kg = 72 booksStep-by-step explanation:(I) Number of identical books = 108Mass of books = 30 kgMass of 150 books = ?Let the mass of 150 books = x kg To find the mass of 150 books we will use ratio and proportion:108 books: 30kg = 150 books: x kgYou can also write it like this because ratio can be written in division:108/30 = 150/xBy cross multiplication:108x = 150*30108 x= 4500Divide both sides by 108108 x/108 = 4500/108x= 41.7Thus the mass of 150 books = 41.7kg( ii ) The number of books that have a mass of 20 kg = ?Let assume that the number of books of mass 20 kg = y booksWe will again use ratio and proportion method.108 books: 30kg = y: 20kgWe can write it as:108/30 = y/20By cross multiplication:108 *20 = 30y2160= 30yDivide both the terms by 302160/30 = 30y/3072 = yTherefore the number of books that have mass 20kg = 72 books ....