abhishekik wrote:

My ans is also C.17.

Explanation:

1 also gives 1 remainder when divided by 3, another number is 4, then 7 and so on.

Hence we have an arithmetic progression: 1, 4, 7, 10,..... 49, which are in the form 3n+1.

Now we have to find out number of terms.

tn=a+(n-1)d, where tn is the nth term of an AP, a is the first term and d is the common difference.

so, 49 = 1+(n-1)3

or, (n-1)3 = 48

or, n-1 = 16

or, n = 17

Hello,

I like this solution using the arithmetic progression but in the expression

tn=a+(n-1)d why

n-1 and not

n ?

As I know Un= U0 + n r where U0 is the first terme and r is the common difference.

Thx in advance for the lighting !

_________________

The Kudo, please