GMAT paper test - decimal notation

[tanyajoseph]

What is the least no of digits (including repetitions) needed to express 10^100 in decimal notation?

a) 4
b) 100
c) 101
d) 1000
e) 1001

[kajcha]

Should be 101

[tanyajoseph]

That is the the correct answer but it would be useful for the users if you could post the detailed work out:)

[samirpandeyit62]

Hi Tanya & Kajcha,

10^100 will give u an integer nos as

10000..... (total 100 0's)

so total nos of digits is 101 (one 1 & 100 0's)
this wud be total nos of digits reqd to express this nos in INTEGER form

now an integer say 10 can be represented in a decimal form as
10.0 (1 zero added after decimal pt)

so here the ans should be 102
any thoughts on this??

[kajcha]

samir, I won't agree with that... We can write 10 or 10.0 in decimal format. So, I don't think we really need to go that far... again, that's my opinion...

tanya, my explanation is same as samir's

[samirpandeyit62]

Kajcha, I quiet agree with u, I just mentioned this coz in true mathematical sense an integer is a nos with no decimal pt & a decimal is a nos with a decimal pt. Well anyways I would have also selected 101 here.

[niks_01.27]

Hey Guys... as what I understand a decimal notation is the writing of numbers in the base-ten numeral system, which uses various symbols (called digits) for no more than ten distinct values (0, 1, 2, 3, 4, 5, 6, 7, 8 and 9) to represent any numbers, no matter how large. Though these digits are often used with a decimal separator which indicates the start of a fractional part but it's not necessary and/or mandatory.

So, as all agree answer should be 101