Question

How many three-digit numbers can be formed using the digits 0 and 7? Repeated digits are allowed.

Answer 1

how many digit are there between 0 to 7?

Answer 2

8

Answer 3

making a tree diagram makes this thing huge

Answer 4

but its only the digits 0 an7 so that doesnt matter how many are in between

Answer 5

so we have to think of it logically;

we have 8 choices; which have 8 choices, making 8*8 = 64 choices
we have another 8 choices for each of those; 64*8 = 8^3

8*8*8 = 8^3 = number of options total

Answer 6

Oh, it is just 0 and 7
so you have two choices for each digits

2 * 2 *2 =8

Answer 7

think of a tree that has 8 branches, named 01234567

each branch has 8 more branches ... with 8 more branches extending from thos as well

Answer 8

.... and the 0 i spose makes for complication lol

Answer 9

its only the digits 0 and 7

Answer 10

there are 000 to 099 that we can omit I spose?

Answer 11

so its not as complicated as we think

Answer 12

I believe my last response was right

Answer 13

But we have two digits and 3 spaces ..

Answer 14

why would it be 2 * 2* 2?

Answer 15

lol ... this belongs in the writing section ;) maybe

Answer 16

two choices for first digit 0,7
two choices for second digits 0,7
two choices for third digits 0,7
2*2*2=8

Answer 17

000
007
070
700
077
707
770
777

is that all of them?

Answer 18

yeah got it

Answer 19

aint that 3C2 as well?

Answer 20

okay thank you!

Answer 21

Not combination or permutation because numbers are allowed to repeat

Answer 22

yeah