Question

What will be the remainder when 3^99 is divided by 5?

Answer 1

3^2 mod 5 = 4
3^3 mod 5 = 2
3^4 mod 5 = 1
3^5 mod 5 = 3

3^6 mod 5 = 4
3^7 mod 5 = 2
3^8 mod 5 = 1
3^9 mod 5 = 3

Answer 2

hmmm I ended up with a 7

Answer 3

or so the calculation said =)

Answer 4

okay, thank you all! :)

Answer 5

yw

Answer 6

3 ^ 99 = 3^3 * 3^96 = 3^3 * (3^4)^24 = 3^3 * 81^24 = ....7

if a big number which has the unit digit is 7 when divided by 5 then its remainder is 2