Question

find the sum of first ten even positive integers

Answer 1

the sum of first ten even positive integers is 2+4+6+8+10+12+14+16+18+20=110

Answer 2

first ten even positive numbers = 2,4,6......20
they are in AP 
a=2           l=20
d=2
n=10sum of first ten even positive integers=n/2(a+l)
                                                                    =10/2(2+20)
                                                                    =5(22)
                                                                     = 110