At 40degC, heptane has a vapor pressure of about 91.5 torr and octane has a vapor pressure of about 31.2 torr,. Assuming ideal behavior, what is the vapor pressure of a solution that contains twice as many moles of heptane as octane?
a) 61.0 torr
b) 51.3 torr
c) 71.4 torr
d) 81.8 torr
e) none of these