Question

a positive integer n when divided by 9 gives 7 as remainder. find the remainder when (3n-1)divided by 9

Answer 1

Given A positive integer n is divided by 9 gives 7 as the remainder.

Let a be quotient

n = 9a+7

3n-1 is divided by 9

now, 3n-1= 3(9a+7)-1

 =27a + 21-1

 =27a +20  = 27 a + 18 +  2

= 9( 3a + 6) + 2 when divided by 9

Remainder = 2.

Answer 2

Given A positive integer n is divided by 9 gives 7 as the remainder.

Let a be quotient

n = 9a+7

3n-1 is divided by 9

now, 3n-1= 3(9a+7)-1

 =27a + 21-1

 =27a +20  = 27 a + 18 +  2

= 9( 3a + 6) + 2 when divided by 9

leftover = 2