Lizzy: Jeff wanted to rent an apartment to live in for the next 5 years until he finishes his studies. He found a nice apartment next to his school, the owner asks Jeff to pay $300 each month, Jeff agreed, and for the first 3 years everything went fine, but then the owner wanted to raise the price for each month to $350. Jeff agreed again and continued paying until he graduated. How much did Jeff end up paying for the apartment throughout the 5 years?.
Me: Hmmm, let me think. I think this is the detailed solution:
At first Jeff paid, $300 / month x 12 months = $3,600 / year. He paid $3,600 / year x 3 years = $10,800 the firsts 3 years. The final 2 years he paid $350 / month x 12 months = $4,200 / year. He paid $4,200 / year x 2 years = $8,400 the last 2 years. He paid the owner $10,800 + $8,400 = $19,200 in total. Final answer: 19200.