Why can you combine the -3ab and 7ba

During a bike challenge riders have to collect various colored ribbons each 1/2 mile they collect a red ribbon each eighth mile they collect a green ribbon and each quarter mile they collect a blue ribbion wich colors of ribion will be collected at the 3/4 markrer

Arecipe calls for 32 fluid ounces of heavy cream.how many 1 pint containers of heavy cream are needed to make the recipe?

15/16 as a decimal rounded to the nearest hundredth