15% off $30.00 is what percent of 30.00

Zoe placed colored blocks on a scale in science class. each block weighed 0.8 ounces. the total weight of all the colored blocks was 12.8 ounces. how many blocks did zoe place on the scale? write and solve an equation to find the answer.

Mindy bought 5/8 pound of almonds and a 3/4 pound of walnuts.which pair of fraction cannot be used to find how many pounds of nuts she bought in all.

What expression is equivalent to log3(x+4)