Answer: d) 9
Step-by-step explanation:
Step 1: Multiply each digit by the pattern 3, 1, 3, 1, ...
5 x 3 = 15
1 x 1 = 1
1 x 3 = 3
3 x 1 = 3
2 x 3 = 6
0 x 1 = 0
3 x 3 = 9
6 x 1 = 6
2 x 3 = 6
1 x 1 = 1
7 x 3 = 21
Step 2: Find their sum
15 + 1 + 3 + 3 + 6 + 0 + 9 + 6 + 6 + 1 + 21 = 71
Step 3: Subtract the sum from the nearest equal or higher multiply of 10
80 - 71 = 9
