What is the percent by mass of 8.0g copper is added to enough zinc

How many types of federal student aid are available to students ? a: 3 b: 2 c: 5 d: 10

By what percent will the product of two numbers change, if the first number increases by 70%, while the second number decreases by 40%.

17 a tourist was planning a trip by car for travelling at some constant speed for 2.5 hours. however, he found that if he increases the speed by 20 km/h he can cover the same distance in 30 minutes less time than it was planned. what was the planned speed of the tourist, in km/h?