Alright, let's work through 3665 times 15 step by step
3665 × 15 = 15 × (3665)
+ 15 × 5 what gives us 75
+ 15 × 60 that results in 900
+ 15 × 600 which equals 9000
+ 15 × 3000 giving us 45000

= 54975
