Compute the probability of tossing a six-sided die and getting a 7

Which shows the correct solution of the equation 1/2a+2/3b=50, when b=30?

Astore has clearance items that have been marked down by 60%. they are having a sale, advertising an additional 55% off clearance items. what percent of the original price do you end up paying?

If value of cos330° is √3/2 then find tan165°.