x/20 = 108/30
x = 20*108 รท 30 = ....
108 identical books have a mass of 30kg.find the number of such books that has a mass of 20kg.
2 answers
2/3 the mass, so 2/3 the books
2/3 * 108 = 72
2/3 * 108 = 72
19 answers