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2017/08/16 (2)
2017-08-16 20:42:36

Smallest multiple

Problem 5 

2520 is the smallest number that can be divided by each of the numbers from 1 to 10 without any remainder.


What is the smallest positive number that is evenly divisible by all of the numbers from 1 to 20?


Answer 232792560


Code

def gcd(a, b):

    while b != 0:

        a, b = b, a % b

    return a


def lcm(a, b):

    return a*b/gcd(a, b)


lcmNum = 1

for i in range(2,21):

    lcmNum = lcm(lcmNum,i)

    

print(lcmNum)

2017-08-16 20:20:34

Largest palindrome product

Problem 4 

A palindromic number reads the same both ways. The largest palindrome made from the product of two 2-digit numbers is 9009 = 91 × 99.


Find the largest palindrome made from the product of two 3-digit numbers.


Answer

number = 906609


Code

print(max([x*y for x in range(999,900,-1) for y in range(x,900,-1) if str(x*y) == str(x*y)[::-1]]))