#1**+1 **

What are these questions?

Are you supposed to be solving them by hand within a reasonable amount of time?

It's pretty trivial solving them with software.

Thoughts?

Rom Aug 6, 2019

#3**+1 **

Actually, this is a written contest where you have to do 30 questions in 40 minutes by hand, no calculator.

dgfgrafgdfge111
Aug 6, 2019

#4**+2 **

432= 2*2*2*2*3*3*3*1 (times 1 as many times as you want)

So the single digit numbers that go into 432 are 1, 2, 3, 4, 6, 8, 9

To add 4 numbers to 20 I need an even number of even numbers. ie, 0,2 or 4 even numbers

Lets see if i can split 432 into 4 odd single digit factors ...odd, odd, odd, odd This is impossible.

Ok

Lets see if i can split 432 into 2 odd single digit factors and 2 even digit factors ...odd, odd, even, even

9 * 3 * 8 * 2 = 432 But these add to 22 So they are no good

9 * 3 * 4 * 4 = 432 These add to 20

9 * 1 * 8 * 6 = 432 But these add to 24 so they are no good.

3 * 3 * 6 * 8 = 432 These add to 20

AND LASTLY

Lets see if i can split 432 into 4 odd single digit factors ...even, even, even, even

6 * 6 * 6 * 2 = 432 These add to 20

So there are only 3 combinations of digits possible

9 * 3 * 4 * 4 This has the biggest digit so the largest number will be 9443

3 * 3 * 6 * 8

6 * 6 * 6 * 2 This has the smallest digit so the smallest number will be 2666

**9443-2666 = 6777**

Note: I did not use a calculator but I would not get many of this level question done in 40 minutes either.

Still not all the ones you have been asking have been so time consuming.

Melody Aug 7, 2019