Question

the weight of 72 books is 9kg.what is the weight of 40 such books.​

Answer 1

Step-by-step explanation:

weight of 72 book= 9kg

weight of 1 book = 9/72kg

weight of 40 book = 9/72×40kg =5kg

Answer 2

Answer:

We'll apply unitary method here,

weight of 72 book =9kg

therefore, weight of 1 book = 9/72kg = 1/8 kg

hence weight of 40 book = 1/8 x 40 = 5 kg