WHat is the sum of the digits of (10^25) - 361? A) 207 B) 216 C) 225 D) 234 E) 241

shankar.ashwin wrote:WHat is the sum of the digits of (10^25) - 361? A) 207 B) 216 C) 225 D) 234 E) 241 A. 207 There will be 21, 9's followed by 639 (639+361=1000). so sum will be 21*9+6+3+9=189+18=207.

shankar.ashwin wrote:WHat is the sum of the digits of (10^25) - 361? A) 207 B) 216 C) 225 D) 234 E) 241 Start with an easier example: 10^4 - 361 = 10,000-361 = 9639. Notice that 10^4 is a 5-digit integer -- the smallest possible. When we subtract 361, the result is a 4-digit integer whose 3 rightmost digits are 6, 3, and 9. The remaining digit is 9. 10^25 is a 26-digit integer -- the smallest possible. Thus, when we subtract 361, the result will be a 25-digit integer whose 3 rightmost digits are 6, 3, and 9. The remaining 22 digits will each be 9. Sum = (22*9) + (6+3+9) = 216. The correct answer is B.

gmatclubmember wrote:shankar.ashwin wrote:WHat is the sum of the digits of (10^25) - 361? A) 207 B) 216 C) 225 D) 234 E) 241 A. 207 There will be 21, 9's followed by 639 (639+361=1000). so sum will be 21*9+6+3+9=189+18=207. I missed one 9, instead of 21 there will be 22. and hence the answer would be 216

gmatclubmember wrote:shankar.ashwin wrote:WHat is the sum of the digits of (10^25) - 361? A) 207 B) 216 C) 225 D) 234 E) 241 A. 207 There will be 21, 9's followed by 639 (639+361=1000). so sum will be 21*9+6+3+9=189+18=207. I think there should be 22 9's. then answer should be 216. OA please user123321