# Euler problems/31 to 40

(Difference between revisions)

## 1 Problem 31

Investigating combinations of English currency denominations.

Solution:

`problem_31 = undefined`

## 2 Problem 32

Find the sum of all numbers that can be written as pandigital products.

Solution:

`problem_32 = undefined`

## 3 Problem 33

Discover all the fractions with an unorthodox cancelling method.

Solution:

`problem_33 = undefined`

## 4 Problem 34

Find the sum of all numbers which are equal to the sum of the factorial of their digits.

Solution:

`problem_34 = undefined`

## 5 Problem 35

How many circular primes are there below one million?

Solution:

`problem_35 = undefined`

## 6 Problem 36

Find the sum of all numbers less than one million, which are palindromic in base 10 and base 2.

Solution:

`problem_36 = undefined`

## 7 Problem 37

Find the sum of all eleven primes that are both truncatable from left to right and right to left.

Solution:

`problem_37 = undefined`

## 8 Problem 38

What is the largest 1 to 9 pandigital that can be formed by multiplying a fixed number by 1, 2, 3, ... ?

Solution:

`problem_38 = undefined`

## 9 Problem 39

If p is the perimeter of a right angle triangle, {a, b, c}, which value, for p ≤ 1000, has the most solutions?

Solution:

`problem_39 = undefined`

## 10 Problem 40

Finding the nth digit of the fractional part of the irrational number.

Solution:

`problem_40 = undefined`