Question

If the variance of a discrete random variable x is v(x) = 1.6, then v(2x + 3) is

Answer 1

Adding an offset to the data changes the mean, but not the variance. Multiplying the data by a constant changes the variance by the square of that constant.
v(a·x) = a²·v(x)

You will have v(2x+3) = 2²·v(x) = 4·1.6 = 6.4