Help for this one !!

Remainder of any no. divided by 10, is the unit digit

Remainder of any no. divided by 5, is the unit digit (if it is 0,1,2,3,4) or unit digit - 5 (if it is 5, 6, 7, 8, 9)

So, you just need to figure out the unit digit of z and you can solve the rest

9^1=9

9^2=81

9^3=729

so for even power, the last digit is 1

similarly for 4

4^1=4

4^2=16

4^3=64 etc…

so for even power, it ends with 6

so the last digits can be 7(even power) or 3(odd power) now 7/5 has reminder 2 and 7/10 has a reminder of 7 B is greater

9+4 = 13/5 rem 3, 13/10 rem 3

81+16 = 97/5 rem 2, 97/10 rem 7

…and so on

For every odd power, rem is 3 for z/5 and z/10

For every even power, rem is 2 for z/5 and 7 for z/3

Since, the power in the given question is even,

For z/5, rem will be 2 and for z/10, rem will be 7

So, the answer is B.

I am thinking.