Alright, let's work through 9885 times 3161 step by step
9885 × 3161 = 3161 × (9885)
+ 3161 × 5 producing 15805
+ 3161 × 80 giving us 252880
+ 3161 × 800 yielding 2528800
+ 3161 × 9000 resulting in 28449000

= 31246485
