Explanation

To find the time it takes for the amount to reach Rs. 784:

Use the formula for compound interest:

A = P(1 + r/n)^(nt)

where A = 784, P = 700, r = 4% = 0.04, n = 1 (compounded annually)

784 = 700(1 + 0.04/1)^(1t)

Divide both sides by 700:

1.1286 ≈ (1.04)^t

Take the logarithm of both sides:

t ≈ log(1.1286) / log(1.04)

≈ 3

So, it will take approximately:

3 years