Given information:
- Principal amount (P) = Rs. 9360
- Time period (t) = 7 years
- Rate of interest (r) = 8%

Calculating simple interest:
The formula to calculate simple interest is:
Simple Interest (SI) = (P * r * t) / 100

Using the given values:
SI = (9360 * 8 * 7) / 100 = 5236.80

Calculating the amount:
The amount (A) can be calculated using the formula:
A = P + SI

Substituting the values:
A = 9360 + 5236.80 = 14596.80

Therefore, the amount after 7 years is Rs. 14596.80.

Calculating the time to double the amount:
To find the time it takes for the amount to double, we can use the formula:
Amount = P * (1 + r/100)^t

Substituting the given values:
14596.80 = 9360 * (1 + 8/100)^t

Simplifying the equation:
(1.08)^t = 14596.80 / 9360
(1.08)^t = 1.560156

Taking the logarithm of both sides:
t * log(1.08) = log(1.560156)
t = log(1.560156) / log(1.08)

Using a calculator, we find:
t ≈ 9.04

Therefore, it will take approximately 9.04 years for the amount to double at a simple interest rate of 8%.

Explanation:
- The given problem involves finding the amount of money after 7 years with a simple interest rate of 8% and then calculating the time it takes for the amount to double at the same rate.
- Initially, we calculate the simple interest using the formula SI = (P * r * t) / 100, where P is the principal amount, r is the rate of interest, and t is the time period.
- Using the given values, we find that the simple interest is Rs. 5236.80.
- To find the amount after 7 years, we add the principal amount to the simple interest, which gives us Rs. 14596.80.
- Next, we use the formula A = P * (1 + r/100)^t to calculate the time it takes for the amount to double.
- Substituting the given values, we simplify the equation and find that t ≈ 9.04 years.
- Therefore, it will take approximately 9.04 years for the amount to double at a simple interest rate of 8%.