Question

find unit digit of 52^5!​

Answer 1

Answer:

2

Step-by-step explanation:

525=(50+2)5=505+5×504×2+10×503×22+10×502×23+5×50×24+25

From this expansion, it should be obvious to you that every term bar the last is a multiple of 10, so they can not contribute to the unit digit. Thus, the unit digit can only arise from the last term, namely 25.

25=32=30+2

A1: The last digit of 525 is 2.