Three pens and two notebooks cost 86 rupees. Two pens and three notebooks cost 89 rupees. What is the price of one pen?

Correct answer: 16 rupees

This word problem is modeled by a pair of linear equations. Let p be the price of one pen and n the price of one notebook. The statements give 3p + 2n = 86 and 2p + 3n = 89. To eliminate n, multiply the first equation by 3 and the second by 2: 9p + 6n = 258 and 4p + 6n = 178. Subtracting the second result from the first gives 5p = 80, so p = 16 rupees. Substituting into 2p + 3n = 89 gives 32 + 3n = 89, hence n = 19. A check gives 3(16)+2(19)=48+38=86. Therefore option A is correct; 19 is the notebook price, not the pen price.