First calculate the future value of the annuity
The formula to find the future value of an annuity ordinary is
Fv=pmt [((1+r/k)^(kn)-1)÷(r/k)]
Fv future value?
PMT quarterly payment 1500
R interest rate 0.12
K compounded quarterly 4
N time 4 years
Fv=1,500×(((1+0.12÷4)^(4×4)
−1)÷(0.12÷4))
=30,235.32
Now compare the amount of the annuity with amount of the gift
30,235.32−30,000=235.32
So as you can see the amount of the annuity is better than the amount of the gift by 235.32
Second offer is better
Hope it helps!
Remember that the slope of a line never changes, so you can choose whatever 2 points you want and you will always get the same slope. Calculate the rise and run (You can draw it on the graph if it helps). The slope is 2/4, which , of course, you can simplify to ½.
