digits

[baller12q]

If N is a positive interger, is the Units digit of N equal to zero?

1) 14 and 35are factors of N

2) N= (2^5) (3^2) (5^7) (7^6)

[scoobydooby]

Units digit of N equal to zero?

1) 14 and 35 are factors of N
=> 14=2*7, 35=7*5
if 14 and 35 are factors of N, then 2,5,7 are factors of N.
if 2 and 5 are both factors of N then 2*5*7*a*b*... will give the last digit as 0, as 2 *5 makes 10 and anything multiplied by 10 gives the last digit as 0
sufficient


2)N= (2^5) (3^2) (5^7) (7^6)
=> N= (2*5)^5*(3^2)*(7^6)*(5^2)
=> N=10^5 *(3^2)*(7^6)*(5^2)
will give the last digit as 0 as powers of 10 multiplied by any number will give 0 as the last digit
sufficient

hence D

[baller12q]

i dont understand what you did in statement 2 cn you please help me clear that up

[scoobydooby]

2)N= (2^5) (3^2) (5^7) (7^6)

in fact we need not do any groupings or rearranging. as long as we have a 2 and a 5 we get 10 and anything multiplied by 10 results in 0 as the unit digit. so statement 2 is sufficient