We have the lease of a building is for 10 years with an annual rent of $48 000.
We first determine the 7.5% for the first 5 years, for that we add the cost of the rent for 5 years, that is:
In 5 years the rent will be of $240 000, now we find the 7.5%:
Her commision for the first 5 years is going to be of $18 000.
Now we determine the 5% for the next 3 years, for this we determine the rent for 3 years:
The rent for 3 years adds $144 000, now we determine the 5%:
From this we have that the commission for the next 3 years will be of $7200.
And finally, we determine the rent for the two remaining years:
We have that the last two years the rent will be of $96000, now we determine the 3.5% of her commission during that time:
From this we have her commission for the last two years will be of $3360.
Finally we add all of the values of the commissions she will get:
From this we have that the total commision money she will be getting during those 10 years will be $28 560.