# digit

1. ### Basic Digit Problems

Question: What is the product of 23 and 79 to one place of accuracy? 1600 or 2000. Seeking help. Thanks. Regards, Mushfique
2. ### Digit Arrangement

Hello! This is what I have done: a) We can choose from 6 numbers for the first digit ( we exclude 0), 6 digits for the second (we exclude the first but include 0) and finally 5 digits for the third (we exclude the first and second). So total number of possibilities = 6 *6 *5 = 180 ways b) I...
3. ### Unit's digit problem

Hello Find the units digit of 7^7^7^7.... Please provide some hints. Thanks
4. ### Find unit's digit

Hello Find unit's digit of 7^11^13^17 Solution : evaluate 11^13^17 = 2431 cyclicity of 7 is 4 2431%4=3 So unit's digit of 7^2431 is same as unit's digit of 7^3 = 3 Is there any method to solve this problem without evaluating 7^11^13^17? Thanks
5. ### Sum of even digit f the number

Let P(n) denote the sum of the even digits of the number "n"\;, foe example: P(8592) = 8+2 = 10\;, Then value of \displaystyle \sum_{r=1}^{100}P(r) =
6. ### Significant digit? how to work this out?

Hi. I would like to ask those that have done a bit on computational Maths. I thought I understood it but my lecture notes gives another example and i don't get it: It reads: actual value = 23.496 and estimate = 23.494 The the error is |actual - estimate|= 0.002. The actual value has four...
7. ### How many 4 digit numbers

How many 4 digit numbers between 3,000 and 7,999 contain at least one 2? How do I set this up?
8. ### Leading digit in decimal notation

Hello! I have this problem: How many of the numbers 2^m, for 0<=m<=M, have leading digit 1 in decimal notation?
9. ### Which are the digits that never appear in any units' digit of any square number?

He's a maths problem I am stuck with... Thanks for your help in advance. List the digits that will not be in the units' digit of any square number? (please show clear reasoning)
10. ### Can Math Guess the Next 3 Digit Combination?

Hey there, just curious, if we have a game (say, lottery) and the game lets us choose a 3 digit combination from numbers 1 to 9 (repeating), can we somehow predict the next three digit combination?? I have seen a formula for this but i doubt its effectiveness. Just wondering.
11. ### probability of repeating digit

Hi! What is the probabilty that in a 10-digit number, digit 7 repeats 6 times (no more or less, exactly)? or in other words, what is the probability that in a random 10-digit number there will be 6 sevens. thanks
12. ### 13th and 20th digit

find 13th and 20th digit of 13202013
13. ### 8 digit number

Find a 8 digit number which starts with 1984 and is divisible by 6,7,8,9.Step by step explanation will be appreciated.

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15. ### Find the 2013th digit after the decimal point in the expression of...

Let m=\frac{\sqrt{10^{4024}-1}}{3} Find the 2013th digit after the decimal point in the expression of \sqrt{m} It seems a similar problem. xkcd &bull; View topic - math problem - driving me crazy But I don't think so. I can't write m to (\sqrt{a}+\sqrt{b})^n a,b,n is integer numbers
16. ### Number of sequences of 8 digits where no digit occurs exactly 3 times?

Consider the problem of counting the number of sequences of 8 digits where no digit occurs exactly 3 times. (a) Solve this problem by the method of inclusion and exclusion. (b) Solve this same problem by the method of exponential generating functions. I am having trouble getting started...
17. ### What is the units digit of the following number (sum of powers)

Hello. I'm having problems solving this problem. What is the units digit of the following number: (1- \sqrt{3} )^{2000} + (1+ \sqrt{3} ) ^{2000} I wouldn't have any problems solving this, were it not for the square root of 3. Please, help.
18. ### probability of correctly guessing 1,2,3 or 4 digits out of 4 digit number

I have two questions and it's a little more complicated than the title implies. I just spent almost 2 hours reviewing basic probability and reading lottery-related websites and I just don't have time to keep going with this on my own (I'm making a game and it's nothing to do with lotteries...
19. ### Unit digit

What is the unit digit of the expansion (44)^4,(55)^5,(88)^8.. I want the deep explanation... Please..(Crying)
20. ### Four digit integer, unable to solve, confusing

A positive four digit integer abcd has the following properties a>b>c>d a=b+c b=c-d If M is highest possible value for abcd What is the value of M?