Bank account value X(t) follows SDE as dX(t) = pdt + odW(t). For first two years, bank account has drift and volatility as 2 and 3, respectively. For the next three years, the drift and volatility are changed as 3 and 4, respectively. If initial amount of bank account is 0, at the end of 5 years the probability distribution function follows N(a,b) with drift a and variance b. Please find a and b. (Hint: First two years and next three years are not correlated) a is bis