Sony bought 80 pens at rs 12 each and sold 15 pens for rs 242 at what price must remaining pens be sold to gain 20% on whole transaction

72 pens

Step-by-step explanation:

80*12 = 960

960*1.2 = 1152

242/15 = 16.1333333333

1152/16.1333333333 = 71.4049586778

71.4049586778 rounds up to 72 pens.

option (b) is correct

step-by-step explanation:

to find the solution of this system, we need to convert it into reduced row-echelon form. we have,

after applying row operations r2 -> r2/2 and r3 -> r3/3, we get,