6-1) (Math: pentagonal numbers) A pentagonal number is defined as n(3n–1)/2 for n = 1, 2, . . ., and so on. Therefore, the first few numbers are 1, 5, 12, 22, . . . . Write a method with the following header that returns a pentagonal number: public static int getPentagonalNumber(int n) Write a test program that uses this method to display the first n pentagonal numbers with 10 numbers on each line, one space between each number, and the user entering the integer value for n.

7. the cullerton park district holds a mini-olympics each summer. create a class named participant with fields for a name, age, and street address. include a constructor that assigns parameter values to each field and a tostring() method that returns a string containing all the values. also include an equals() method that determines two participants are equal if they have the same values in all three fields. create an application with two arrays of at least eight participants each—one holds participants in the mini-marathon, and the other holds participants in the diving competition. prompt the user for participant values. after the data values are entered, display values for participants who are in both events. save the files as participant.java and twoeventparticipants.java.