Jeff wants to buy a phone card for long distance calls. he can buy a 200-minute card for $10.00 or a 300-minute card for $12.00. which card is the better value

200 min / $10.00 = 20 minutes / dollar 

300 min / $12.00 = 25 minutes / dollar 

The cost of the 300 minute card is cheaper per minute and a better value. 

If you don't expect to use more than 200 minutes then save your money and buy the smaller card.

300 Minute card.

It's 20 mins per $1 for the $10 plan. using the same pricing you would only get 240 mins for $12. So 300 for $12 is the better deal.

Its a right angled triangle not a right triangle