we wiil use the ncr or the npr and why
So, there are 10 digits that could go in the first spot and there are 10 digits that could go in the second spot. 10 X 10 is equal to what?
what is the meaning of 0 through 9
Its basically saying how many combinations can you get with the numbers 0 through 9. Order does matter since this is a telephone number. With 0 as the lead coefficeint you can have: 0 0 0 1 0 2 0 3 0 4 0 5 0 6 0 7 0 8 0 9 So you can have 10 combinations when 0 is the lead. Well you will get 10 more when 1 is the lead, 2 is the lead, 3 is the lead, 4 is the lead, 5 is the lead, 6 is the lead, 7 is the lead, 8 is the lead, and 9 is the lead. Add them all up and you get 100.
You get it?
i get your think but i want to know can i do it by calc using the npr or the ncr
too much work there are 100 two digit numbers use nothing but common sense
and if i do it by the npr its come 90 not 100
You don't need npr or ncr it's a logic question... very simple question at that.
You can also think of a 10x10 table (10 rows, 10 columns) so there would be 10*10 = 100 entries. The entries would be this sequence 00,01,02,...,97,98,99
Yes exactly it's so simple that using something so complex will give you the wrong answer
Trust me I had this same question Last Year and made the same mistake you did.
but i need to know bec the my mr asking me i will use the ncr or the npr or none
i said to him none
Yes you won't use it because none is required
ok thnak u @shelbygt520
u are the best
npr and ncr are only used if repeated digits are NOT allowed but in this case, a phone number like 555-0202 is possible. So repeated digits are allowed
and u too@jim_thompson5910
ok bie friends
sorry but can i use the digit 10 @shelbygt520
or only 123456789
No because you are only aloud to use digits 0 through 9 or 0123456789
ok but if i aloud the 10 they wiil be 11*11
write or wrong
"10" is composed of "1" and "0" shelbygt520 has the right idea
no because 10 would be 2 digits making it impossible to use it and another digit so you would essentially end up with 101
although as @jim_thompson5910 said 10 is composed of the digits 1 and 0 making it a combination within itself.
oh ya thanks friends
so the q can write as how many 2-digits formed from 0,1,2,3,4,5,6,7,8,9 @shelbygt520
write or wrong
what i writ wrong or write
yeah how many ways to make a 2 digit number
can i write it like this so the q can write as how many 2-digits formed from 0,1,2,3,4,5,6,7,8,9 write or wrong
yeah that's one way to think of it how many ways to form a 2 digit number
the other digits of the phone number don't matter
thank u @jim_thompson5910