Question

How many even numbers can be made from number 2567 if digits can't repeat. How I think:

One digit number: 2
Two digits number: 2*2=4
how to find three and four digit numbers?

Answer 1

if the last digit is 2 then there are \(3!=3\times 2=6\) choices for the other three

Answer 2

and if the last digit is 6, then there are still \(3!=6\) choices
so the total is \(6+6=12\)

Answer 3

well, i did it like it, but there numbers with 4 digits, right? And the answer is 32, so I think something is incorrect

Answer 4

oh sorry, i thought you had to use all the digits

Answer 5

oh, actually i dont know. the problem sounds like this: "How many even numbers can be made from number digits 2567, if digits cant repeat". Do I need to use all numbers? Cant it be any one digit, two digit numbers?

Answer 6

@satellite73 are you here?

Answer 7

@hartnn

Answer 8

can you help me?

Answer 9

even i get 12 even numbers using same logic as of satellite.

Answer 10

Oh, i think it can be: One digit numbers: 2, 6 (2 numbers), two digit numbers (12;16;26;56;52, etc) - 8 numbers, three digit numbers (12 of them). Isnt it correct?

Answer 11

oh, so not necessarily 4 digit number.
you need to add number of 1 digits nos. + number of 2 digits nos. +number of 3 digits nos. +number of 4 digits nos.
and 12 is the number of 4 digits number.

Answer 12

Can you show me step by step?

Answer 13

One digit number: 2
Two digits number: 3C1*2=6
3 digit number = 3C2 * 2! = 6*2 = 12
4 digit number = 3! *2! = 12
2+6+12+12 = 32

Answer 14

thanks:)

Answer 15

only 6 two digit number
12;16;26;56;52;62

Answer 16

welcome ^_^