In an A.P., the first term is 2, the last term is 29 and the sum of the terms is 155. Find the common difference of the A.P.
Answers
Answered by
0
Answer:
use formula Sn = n/2(a+tn) and tn = a+(n-1)d
Attachments:
Answered by
2
d = +3
Step-by-step explanation:
(i) Given: In an A.P., the first term is 2, the last term is 29 and the sum of the terms is 155.
Find: d
a = 2
Sum = 155
an = 29 = a + (n-1)d
So 2a + (n-1)d = an + a = 29 + 2 = +31
Now Sum = n/2 (2a + (n-1)d)
155 = n/2 (31)
n = 155 *2 / 31
n = 10
Substituting n in an, we get: 2 + 9d = 29
9d = 27
d = +3
AP will be 2, 5, 8,........26, 29.
Similar questions