Last week donnell practiced the piano 3 hours longer than marcus together marcus and donnell practiced the piano for 11 hours. for how many hours did each young man practice the piano?

In the field of thermodynamics, rankine is the unit used to measure temperature. one can convert temperature from celsius into rankine using the formula c= r/1.8 - 273, what is the temperature in celcius corresponding to r degrees rankine.

The jewelry store is having a sale. necklaces that were regularly priced at $23.50 are on sale for $18.80. what is the percentage of decrease in the price of necklaces?

In trapezoid abcd, ac is a diagonal and ∠abc≅∠acd. find ac if the lengths of the bases bc and ad are 12m and 27m respectively.