CAT4MBA

Hi
i think ans would be -1 or 16

ans is 10

Little Star

hi can u explain it in detail hwz it 10 for me it was coming 16 i applied euler theorem,plz do explain

Me too thinks the Answer is 10

accordin 2 fermats theorem,
(a^(p-1))/p givs remainder =1
where p is prime num and a is not div. by p
so 20^16 div by 17 givs remainder =1
20^51=20^48 *20^3 remainder = 1*10=10 
10^97=10^96 *10=1*10=10

The above said approach is correct only when the problem is stated like :

(20^51)^97 (i.e 20 to the power of 51 whole to the power of 97). But if it is 20^51^97, then that approach is wrong. Because, a^b^c doesn't mean a^bc.

Example: 2^3^4 =2^81 but not 2^12.

Answer 10 is correct..
Last two digits of 51^97=51
Now,
20^51^97(mod 17)
=20^(..51)(mod 17)
=20^3(mod 17)[Applying FLT,As 20^16%17=1]
=3*3*3(mod 17)
=10..

Giv ur best to the world.
Nd d best will cm back to you...

Regards,
Dipanjan....