Thursday
July 31, 2014

Homework Help: Discrete Math

Posted by Francesca on Tuesday, April 12, 2011 at 10:55am.

Is this correct?

Using the Principle of Inclusion-Exclusion, find the number of integers between 1 and 2000 (inclusive) that are divisible by at least one of 2, 3, 5, 7.

A = {n| 1 ≤ n ≤ 2000, 2 |n}
B = {n| 1 ≤ n ≤ 2000, 3 |n}
C = {n| 1 ≤ n ≤ 2000, 5 |n}
D = {n| 1 ≤ n ≤ 2000, 7 |n}

|A| = [2000/2] = 1000
|B| = [2000/3] = 666
|C| = [2000/5] = 400
|D| = [2000/7] = 285

Also, I'm kind of confused with how to approach this problem:

John Sununus was once the governor of New Hampshire, and his name reminds one of the authors of a palindrome (a words which is spelt the same way forwards as backwards, such as SUNUNUS).

How many seven-letter palindromes (not necessarily real words) begin with the letter S and contain at most three letter?

Thanks for any helpful replies!

Answer this Question

First Name:
School Subject:
Answer:

Related Questions

Discrete Math - 1.Using the principle of inclusion-exclusion find the numbers of...
discrete math - Find how many positive integers with exactly four decimal digits...
Math - What is the smallest natural number divisible by each of the integers 1-...
DISCRETE MATH - HOW MANY POSITIVE INTEGERS LESS THAN 1000 A.are divisible by ...
Easy Math - The number of positive integers that are less than 500 and that are ...
Math - What are the positive integers between 1 and 100 that are only divisible ...
math - Using the numbers 1 through 9 with no repeats, find a 9 number such that...
algebra - how would i find least common multiple of 20, 50 and 3 ? okay well you...
Math - The question is this: You know that a number is divisible by 6 if it is ...
Math - The sum of the integers from 40 to 60, inclusive, is 1050. what is the ...

Search
Members