Elitmus
Exam
Numerical Ability
Number System
Find the sum of its last five digits (2020202) ^4
Read Solution (Total 11)
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- this is equal to 2^4*(1010100+1)^4.
now use binomial.
2^4*[(1010100)^4+4*(1010100)^3+6*(1010100)^2+4*(1010100)+1].
so last 5 digits=16[6*10000+40400+1]=16*00401=06416.
so sum=17 - 10 years agoHelpfull: Yes(36) No(4)
- the answer will be 17
- 10 years agoHelpfull: Yes(3) No(0)
- Right ans is 18 =16*0405
- 10 years agoHelpfull: Yes(1) No(7)
- 7=00016
Thats it
- 10 years agoHelpfull: Yes(0) No(7)
- Right ans is 18 =16*0405
- 10 years agoHelpfull: Yes(0) No(7)
- answer should be 36
- 10 years agoHelpfull: Yes(0) No(3)
- answer is 17
- 10 years agoHelpfull: Yes(0) No(0)
- Answer is 17 and it is 100% sure
- 9 years agoHelpfull: Yes(0) No(0)
- ans is 23 not 17
- 9 years agoHelpfull: Yes(0) No(0)
- ans is 22 bcoz 2020202^2=last five digits=20804*2020202=last five digits=82408
so sum is 8+2+4+0+8=22 - 8 years agoHelpfull: Yes(0) No(0)
- let's multiply only last 5 digit (20202)^4=(20001+201)^4
=((20001+201)^2)^2
=(00001+40001+2*20001*201)^2) (a+b)^2 considering only last five digit
=(00001+40001+40402)^2
=(80404)^2
= 03216 =12ans; or use (20001+201)^4 through binomial expansion - 8 years agoHelpfull: Yes(0) No(0)
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