Save 1.4 million yuan every year, with an average annual return on investment of 20%. After 40 years, the wealth will increase to102,865,438+00,000 yuan. Solving mathematical problems

The annual return on investment is ((3300-40000/24) *12)/80000 = 25%.

This is about 25%, and the annual rate of return is already very high.

At present, the annual rate of return of urban rental is about 5%, and the annual rate of return of bank loans is about 5%-8%. If the gray income is included, it will not exceed 16%.

Explain that the annual rate of return is actually: [your annual income (3,300 *12)]/[your initial investment is 80,000 yuan], but this is on the basis that your 80,000 yuan remains unchanged. After two years, your 80,000 yuan will become 40,000 yuan, which means that you will reduce 20,000 yuan every year. Then your annual income (3300* 12) minus 20000 divided by 80000 is your annual rate of return.

You are looking back at this formula "((3300-40000/24) *12)/80000 = 25%).

40000/24 is the money you change every month, and 3300-40000/24 is your actual income 1 month. Multiplying this money by 12 is your actual income 1, and dividing it by your total investment is your annual rate of return.