in cliff ’ s impressive rock collection , there are half as many igneous rocks as sedimentary rocks . of the igneous rocks , 3 / 5 are shiny and the rest are matte , while 1 / 5 of the sedimentary rocks are shiny . if there are 30 shiny igneous rocks , how many total rocks does cliff have ?
"we can start with the known quantity and then go on to find the others . shiny igneous ricks are 30 . these are ( 3 / 5 ) of total igneous rocks . ( 3 / 5 ) * total igneous rocks = 30 total igneous rocks = 30 * ( 5 / 3 ) = 50 total sedimentary rocks = 2 * total igneous rocks = 2 * 50 = 100 total number of rocks = 50 + 100 = 150 answer ( d )"
divide(multiply(divide(multiply(multiply(3, 5), 30), 3), 5), 3)