Question

. The sum of 12 terms of the A.P. : - 37,- 33, -29, ... is
1) 245
2) - 180
3) 555
4) 2520​

Answer 1

Answer:

a= -37

d= 4

n= 12

______________

sum=?

_______________

sum= n/2[2a + (n – 1)d]

put the value in the above formula

$sum = \frac{12}{2}( {2 \times( - 37) + (12 - 1) \times 4} )\\ \\ sum = 6 \times ( - 37 \times 2 + 44) = - 108$

therefore option 2 is correct