If 1+2+3+...+n=n (n+1), then 3 (1+3+5+....+89)=? Select the correct option.
A) 6150	B) 6200	C) 6050	D) 6075	E) 5075

Rationale: "explanation : to solve this use the formula of ap , sn = ( n / 2 ) ( a + l ) . . . . . . . . . . . . . . . . ( 1 ) to find n , use = > tn = a + ( n - 1 ) d = > 89 = 1 + ( n - 1 ) 2 = > n = 45 use value of n in ( 1 ) then , sn = ( 45 / 2 ) ( 1 + 89 ) = 2025 ans : - 3 ( sn ) = 6075 answer : d"
Answer: D