The sum of the first 9 positive integers is 45 ; in other words,
1+2+3+4+5+6+7+8+9=45
What is the sum of the first 9 positive multiples of 5? In other words, what is the value of 5+10+15+\cdots+40+45?
Answer Choices
A. 225
B. 250
C. 180
D. 150
E. 450