The pair of points that are equal to x coordinates is (0,0)
6x/6y=6z
X/?Y=1/2Z
36=6
1hole take 1 man x 6 days
1/2 hole needs 1 man with 3 days
An exponential behavior can be observed.
Let x be the number of years she has to wait.
100((1+0.08/12)^12x) = 150
Now solve for x.
log base 1.08/12 of 1.5 = 61.02 approx
12x=61.02
x=5.09 years
Your reasoning and your answer were both correct. Discuss with the teacher. ("Discuss". DON'T fight.)