1) 6 = 2 * 3
10 = 2 * 5
12 = (2*2) * 3
14 = 2 * 7
18 = 2 * (3*3)
20 = (2*2) * 5
2) 75 = 3 * (5*5)
77 = 7 * 11
78 = 2 * 3 * 13
136 = (2*2*2) * 17
150 = 2 * 3 * (5*5)