10^50-74
This topic has expert replies
Source: Beat The GMAT — Data Sufficiency |
-
prindaroy
- Master | Next Rank: 500 Posts
- Posts: 113
- Joined: Thu Jul 16, 2009 11:23 am
- Thanked: 15 times
- GMAT Score:730
The answer is C.
10 ^ 50 = 51 digits, i.e 10^2 = 100 = 3 digits, 10^3 = 1000 = 4 digits, etc...
so 10.........-74 = 999999........26 with 50 digits in total. So now, 2+6+(9*48)
= 440
10 ^ 50 = 51 digits, i.e 10^2 = 100 = 3 digits, 10^3 = 1000 = 4 digits, etc...
so 10.........-74 = 999999........26 with 50 digits in total. So now, 2+6+(9*48)
= 440
-
gmat740
- MBA Student
- Posts: 1194
- Joined: Sat Aug 16, 2008 9:42 pm
- Location: Paris, France
- Thanked: 71 times
- Followed by:17 members
- GMAT Score:710
Can you explain the step marked with Bold.prindaroy wrote:The answer is C.
10 ^ 50 = 51 digits, i.e 10^2 = 100 = 3 digits, 10^3 = 1000 = 4 digits, etc...
so 10.........-74 = 999999........26 with 50 digits in total. So now, 2+6+(9*48)
= 440
-
Stuart@KaplanGMAT
- GMAT Instructor
- Posts: 3225
- Joined: Tue Jan 08, 2008 2:40 pm
- Location: Toronto
- Thanked: 1710 times
- Followed by:614 members
- GMAT Score:800
The last two digits are 2 and 6.gmat740 wrote:Can you explain the step marked with Bold.prindaroy wrote:The answer is C.
10 ^ 50 = 51 digits, i.e 10^2 = 100 = 3 digits, 10^3 = 1000 = 4 digits, etc...
so 10.........-74 = 999999........26 with 50 digits in total. So now, 2+6+(9*48)
= 440
The first 48 digits are 9.
So when we sum all the digits, we get 48 9s, one 2 and one 6 to gives us 48*9 + 2 + 6
Stuart Kovinsky | Kaplan GMAT Faculty | Toronto
Kaplan Exclusive: The Official Test Day Experience | Ready to Take a Free Practice Test? | Kaplan/Beat the GMAT Member Discount
BTG100 for $100 off a full course
