Question

i (ii) -5 +(-8)+(-11)+...+(-230) using AP series
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Answer 1

The sum of Arithmetic Progression when first and last term is known, is given as:

n/2 (a + l)

n is unknown

an = a + (n- 1) d

-230 = -5 + (n - 1)(-3)

-230 = -5 - 3n + 3

-230 = -3n - 2

3n = 228

n = 76

Sum = n/2 (a + l)

= 76/2 (-5 - 230)

= 38 (-235)

Sum = -8930