there are , in a certain league , 20 teams , and each team face another team for a total of 10 times . how many games are played in the season ?
"1 st team : 190 2 nd team : 180 3 rd team : 170 similarly the last team will play 0 therefore ( 190 + 180 + 170 . . . . 10 ) 10 ( 19 + 18 + 17 + 16 . . . . 1 ) 10 ( n ( n + 1 ) / 2 ) = 10 ( 19 * 20 / 2 ) = 1900 answer : a"
multiply(multiply(subtract(20, const_1), 10), divide(20, const_2))