Thirty students run in a charity race to raise money for the hurricane victims. Ten of the students raised $20 each. The rest of the students raised $30 each. How much did the students raise in all? Think carefully first, then make a decision:
Ten students raised a total of $20 x 10 = $200. There are 30 - 10 = 20 students who raised $30 each. Twenty students raised a total of $30 x 20 = $600. Therefore, the students raised a total of $200 + $600 = $800. So, the answer is 800.