rohanchowdhary wrote:

Sam spent a total of $6.00 on pens and pencils. How many pens did he buy?

(1) The price of 2 pens was $0.10 less than the price of 3 pencils

(2) The average price of 1 pen and 1 pencil was $0.35

Let's say unit price of pen and pencil are p and q respectively and number of pen and pencil are x and y respectively.

So, we have 4 unknown values and we know that px + qy = 6.00

1) Given that 2p + 0.1 = 3q. However, we cannot solve for 4 unknowns with 2 equations. Insufficient.

2) Given that (p + q) / 2 = 0.35 ==> p + q = 0.7 However, we cannot solve for 4 unknowns with 2 equations. Insufficient.

Together: From the equations 2p + 0.1 = 3q and p + q = 0.7, we get that p = 0.4 and q = 0.3.

Substituting these values into px + qy = 6.00, we get that 0.4x + 0.3y = 6.0

Now we can have different sets of values for x and y (e.g., 3 & 16; 6 & 12) which would satisfy the equation 0.4x + 0.3y = 6.0

Insufficient.

Answer is E.