hhhhhhhhhhhhhhhh
in Word Problem Answers by

Your answer

Your name to display (optional):
Privacy: Your email address will only be used for sending these notifications.
Anti-spam verification:
To avoid this verification in future, please log in or register.

1 Answer

If you mean how many numbers between 1 and 1000 contain 4 then:

Between 1 and 100 we have 4, 14, 24, 34, 40-49, 54, 64, 74, 84, 94 (19). We also have 19 between 100 and 199, then 200-299, 300-399, 500-599, 600-699, 700-799, 800-899, 900-1000. All 100 numbers 400-499 contain at least one 4. So in all we have 9×19+100=217 numbers containing at least one 4.

But 44 (for example) contains two 4s, so 4 appears twice, and in 444 it appears three times. So if we are counting 44 as 2 and 44 as 3 for the number of appearances, we have to add a few more.

For example: between 400 and 499 we have to include double counts for 404, 414, ..., 440-449 and a count of 3 for 444. This gives us 20 4s instead of 19 for 100-199, 200-299, 300-399, 500-599, 600-699, 700-799, 800-899, 900-1000, that is, 9×20=180. For 400-499 we have 100 beginning with 4, and an additional 11 for 440-449, making 111, so 180+111=291 appearances of 4.

by Top Rated User (1.2m points)

Related questions

0 answers
asked Nov 3, 2011 in Word Problem Answers by anonymous | 1.3k views
1 answer
Welcome to MathHomeworkAnswers.org, where students, teachers and math enthusiasts can ask and answer any math question. Get help and answers to any math problem including algebra, trigonometry, geometry, calculus, trigonometry, fractions, solving expression, simplifying expressions and more. Get answers to math questions. Help is always 100% free!
87,516 questions
100,279 answers
2,420 comments
732,244 users