Here is my approach.......
It is given that there are 23 cent costing pencil and 21 cent costing pencil.
From stmt 1, it given that there are 6 pencils in total. From here we cannot say how many 23 cent pencils are there. It can range from 1 to 6. So insufficient.
From stmt 2, it is given the total cost pencils is 130. This means 23x + 21y = 130. Hum one eq and two variables......Is it cannot solve?
Wait a minute......Can we not figure out some random guesses. We should know that here x and y are integers since they represent the number of pencils of each cost.
So we can have at the max 4 - 23 cents costing pencils. So the ans for x will be such that 1<=x<= 4 and 130-23x is divisible by 21. definitely we can find the value of x. Hence sufficient. IMO B.