Please help me with this Ixl answer
 Lyla buys a box of blueberry, poppy seed, and chocolate-chip muffins. There are 20 blueberry muffins and 20 chocolate-chip muffins in the box. Lyla buys the exact same box of muffins 2 days per week. How many muffins are in the box?
 a.72
 b. 71
 c.60
 d.There is not enough information to solve this problem.
 please tell me the correct answer