Which expression has a value of 7/12 ? 7/8 + 4 , 1/3 + 1/4 , 6/8 + 1/4 , 2 1/12 + 5 1/12

With #! i’ve tried to figure it out but i can’t.

Marla bought a book for $12.95, a binder for $3.49, and a backpack for $44.99. the sales tax rate is 6%. find the amount of tax and the total she paid for these items

Weekly wages at a certain factory are normally distributed with a mean of $400 and a standard deviation of $50. find the probability that a worker selected at random makes between $450 and $500