Tuesday, May 23, 1995

Can someone help with word problem?

Jeff and Kirk can build a 75 ft wall together in 4 hours. Because Jeff has more experience, he could build the wall by himself 3 hours quicker than Kirk. How long would it take Kirk, (to the nearest minute) to build the wall by himself?

Answer on Can someone help with word problem?

4X+4Y=75, X=3y, X=Jeff, Y=Kirk
-4(X=3Y)
-4X=-12Y
4X+4Y=75
4Y=75-12Y
16Y=75
Y=4.6875
75/4.6875=16, 16 hours
this answer is only true if they both worked the four hours together