Answer:
The answer is $750 millions
Step-by-step explanation:
After recapitalization, the Weight of Debts of Nichols Corporation is 25%. Hence, its Weight of Equity Capital is: 100% - 25% = 75%. 
The formula of Value of Operations as follows: 
Value of Operations = Weight of Debts x Value of Debts + Weight of Equity Capital x Value of Equity Capital
Because Nichols Corporation's value of operations is equal to $600 million after recapitalization, we have the following equation with S as the value of equity after the recap: 
600 = 25% x 150 + 75% x S 
=> S = (600 - 25% x 150) / 75% = 750