Based on earlier expeditions to a dig site, a geologist expects to find igneous, metamorphic, and sedimentary rocks in the percentages by weight of 25%, 60%, and 15%, respectively. The rock sizes to be found and their percentages of appearance are pebbles (60%), small rocks (20%), medium rocks (15%) and boulders (5%) a What IS the most likely combination of rock type and weight the geatogist will find?