can anyone help me with this school project?

they want me to create something like this :

using Net income = Revenue - costs - salary

net income percentage is by multiplying (Net income)/(Revenue Ratio) with 100%

Handphone net income computation

-----------------------------------

1. Press A to enter Revenue and Costs

2. Press B for Net Income

3. Press C to exit

please enter selection :

Option A

--------

Revenue <please enter 2 dec places > :

Costs <please enter 2 dec places > :

Salary <please enter 2 dec places > :

Handphone net income computation

-----------------------------------

Option B

--------

items amount<$> percentage<%>

----- ----------- ---------------

Revenue (numbers)

Cost (numbers)

Salary (numbers)

====== ========== ============

net income (final answer) (final percentage)

Handphone net income computation

-----------------------------------

1. Press A to enter Revenue and Costs

2. Press B for Net Income

3. Press C to exit

please enter selection : Y <---------(wrong selection)

please enter A, B, or C only.

Handphone net income computation

-----------------------------------

1. Press A to enter Revenue and Costs

2. Press B for Net Income

3. Press C to exit

please enter selection :

umm someone PLEASE HELP ME!