Find the sum of first 20 multiples of 12.	Select.
A) 2520
B) 3878
C) 2778
D) 27
E) 911
Sum of first 20 multiples of 12 are = (12×1) + (12×2) + (12×3) + . . . . . . + (12×19) + (12×20). = 12 (1+2+3+ . . . . . + 20)   Use the formula:   n(n+1) 2   ⇒   12×(20×21) 2   =2520.   2520nswer:2520
<result>A</result>
Find the sum of first 20 multiples of 12.