If Jim earns x dollars per hour, it will take him 4 hours to earn exactly enough money to purchase a particular jacket. If Tom earns y dollars per hour, it will take him exactly 5 hours to earn enough money to purchase the same jacket. How much does the jacket cost?
(1) Tom makes 20% less per hour than Jim does.
(2) x + y = $43.75
We know that
J earns x $/ hour, and the jacket costs 4x
T earns y$/hour, and the jacket costs 5y.
1) INSUF. We knew this information from the data before, because y= 4x/5 =0.8x
We can not calculate the cost of the jacket
2) SUF. We have know another equation, so 2 var. with 2 equations.