Final answer:
The demand for coal will be double that of 1995 in approximately 15 years from 1995, which is the year 2010.
Step-by-step explanation:
To find the year when the demand for coal will be double that of 1995, we need to calculate the number of years it takes for the demand to grow by a factor of 2. We know that the growth rate of the demand for coal is 5% per year. Let's assume that the demand in 1995 is represented by D.
After one year, the demand will be 1.05D (D + 5%). After two years, it will be (1.05D) + 5% of (1.05D), which simplifies to 1.1025D. In general, after n years, the demand will be (1.05)^n * D.
We need to find the value of n that makes the demand double that of 1995. So we can set up the equation: (1.05)^n * D = 2D. By dividing both sides of the equation by D, we get (1.05)^n = 2. Taking the logarithm of both sides, we have n * log(1.05) = log(2). Solving for n, we get n ≈ 14.73. Since n represents the number of years, we round up to the nearest whole number, giving us 15.
Therefore, the demand for coal will be double that of 1995 in approximately 15 years from 1995, which is the year 2010.