Firstly, we have to analyze the task and think of a way to solve it. Then, we will choose data types and, finally, we will write the code.
Let' s first calculate how much the monthly salary of Ivan is. We do that by multiplying the working days per month by his daily earnings. Firstly, we multiply the number by 12, so as to calculate his salary for 12 months, and then, we multiply it by 2.5 in order to calculate the bonus. After having summed the two values, we calculate his annual income. Then, we divide 25% of it. We can do that by multiplying the total income by 0.25 and divide the result by it. Depending on the exchange rate, we exchange the dollars to levs and after that we divide the result by 365 (days per year).