Find the sum : 32 + 30 + 28 +........+ 10.

Question

KnowledgeBoat · Accepted Answer

Let total number of terms in the A.P. be n. We know that, ∴ an = a + (n - 1)d ⇒ 10 = 32 + (n - 1).(-2) ⇒ 10 - 32 = (n - 1).(-2) ⇒ -22 = (n - 1).(-2) ⇒ = (n - 1) ⇒ 11 = n - 1 ⇒ n = 11 + 1 ⇒ n = 12. We know that, Sum of n terms of an A.P. is given by, ∴ Sn = (a + l) ⇒ S12 = (32 + 10) = 6 × 42 = 252. Hence, S12 = 252.

Mathematics

Find the sum :
32 + 30 + 28 +……..+ 10.

AP

Related Questions

Find the sum :
0.6 + 1.7 + 2.8 +….. to 100 terms.

Find the sum :
(-5) + (-8) + (-11) +……. + (-62).

Find the sum of all 2-digit natural numbers divisible by 5.

Mathematics

Find the sum :32 + 30 + 28 +……..+ 10.

AP

Related Questions

Find the sum :0.6 + 1.7 + 2.8 +….. to 100 terms.

Find the sum :(-5) + (-8) + (-11) +……. + (-62).

Find the sum of all 2-digit natural numbers divisible by 5.

Find the sum :
32 + 30 + 28 +……..+ 10.

Find the sum :
0.6 + 1.7 + 2.8 +….. to 100 terms.

Find the sum :
(-5) + (-8) + (-11) +……. + (-62).