Create your Smart Home App in the Free Webinar on Home Automation. Register Now
One of our academic counsellors will contact you within 1 working day.
Click to Chat
1800-1023-196
+91-120-4616500
CART 0
Use Coupon: CART20 and get 20% off on all online Study Material
Welcome User
OR
LOGIN
Complete Your Registration (Step 2 of 2 )
Free webinar on App Development Learn to create your own Smart Home App
16th Jan @ 5:00PM for Grade 1 to 10
Sit and relax as our customer representative will contact you within 1 business day
The numbers of times the digit 3will be written when listing the intiger from 1to 1000
This is P&C question Any number between 1 and 999 can be expressed in the form of xyz where 0 Case 1. The numbers in which 3 occurs only once. This means that 3 is one of the digits and the remaining two digits will be any of the other 9 digits You have 1*9*9 = 81 such numbers. However, 3 could appear as the first or the second or the third digit. Therefore, there will be 3*81 = 243 numbers (1-digit, 2-digits and 3- digits) in which 3 will appear only once. Case 2. The numbers in which 3 will appear twice. In these numbers, one of the digits is not 3 and it can be any of the 9 digits. There will be 9 such numbers. However, this digit which is not 3 can appear in the first or second or the third place. So there are 3 * 9 = 27 such numbers. In each of these 27 numbers, the digit 3 is written twice. Therefore, 3 is written 54 times.Case 3. The number in which 3 appears thrice - 333 - 1 number. 3 is written thrice in it. Therefore, the total number of times the digit 3 is written between 1 and 999 is 243 + 54 + 3 = 300
Post Question
Dear , Preparing for entrance exams? Register yourself for the free demo class from askiitians.
points won -