It is important for Bob to have a gross salary in his fifth year of at least $100,000. He is promised salary increases of 3 percent per year in the second and third years and 5 percent thereafter. What must be his starting salary be to achieve his goal? My original answer was $87,000, but I think $86,000 might work. All of the percents are running together in my head. I think I will go get a Coke. Thanks in advance for your help.

salary in 1st year --- x

salary in 3rd year = x(1.03)^2
salary in 4th year = x(1.03)^2 (1.05)
salary in 5th year = x(1.03)^2 (1.05)^2

x(1.03)^2 (1.05)^2 = 100000
x = 100000/((1.03)^2 (1.05)^2)
= $87,180.84

WOW! Thanks, I had trouble setting up the equation to solve. But it makes sense, like when solving an interest problem.

To find Bob's starting salary, we can work backwards using the given information and set up an equation.

Let's break down the problem step by step:

1. In the second and third years, Bob receives a 3% salary increase annually.
- Starting with the initial salary, after the first year, Bob's salary will be increased by 3%.
- After the second year, Bob's salary will be increased by another 3% on the new salary.

2. In the fourth and subsequent years, Bob receives a 5% salary increase annually.
- After the third year, Bob's salary will be increased by 5% each year.
- This will continue for the remaining years.

Based on these conditions:

- After the first year: Bob's salary remains the same.
- After the second year: Bob's salary is increased by 3%.
- After the third year: Bob's salary is increased by another 3% on the new salary.
- After the fourth year and beyond: Bob's salary is increased by 5% each year.

To find the starting salary that would achieve a gross salary of at least $100,000 in Bob's fifth year, let's work backwards:

Let's assume Bob's starting salary is "S."
- After the first year, Bob's salary remains the same: S.
- After the second year, his salary increases by 3%: S + 0.03S = S(1 + 0.03) = 1.03S.
- After the third year, his salary increases by another 3% on the new salary (1.03S): 1.03S + 0.03(1.03S) = 1.03S(1 + 0.03) = 1.03S(1.03).
- After the fourth year, his salary increases by 5% each year: (1.03S)(1.05).
- After the fifth year: (1.03S)(1.05)^2 (since the increase only applies for the fourth year and beyond).

So, we can set up an equation to find the starting salary:

S * (1.03) * (1.03) * (1.05)^2 >= $100,000.

Now we can solve this equation to find the minimum starting salary that would achieve a gross salary of at least $100,000 in Bob's fifth year:

S * 1.09215 >= $100,000.

S >= $100,000 / 1.09215.

S >= $91,494.68.

Therefore, Bob's starting salary must be at least $91,494.68 to achieve his goal of a gross salary in his fifth year of at least $100,000.

Based on this calculation, your original answer of $87,000 is not sufficient. However, $86,000 is even lower, so it would not meet the requirement either.

Feel free to double-check the calculations or ask any further questions if needed. Enjoy your Coke!