The sum of the first six terms oa an AP is 42.the ratio fo the 10th term to 30th term of an ap is 1/3.calculate the first term and the 13th term.
Asked by DAVID
21st January 2019,
6:36 AM
Answered by Expert
Answer:
Let a be the first term and d be the common difference
Sum of 6 terms = S6 = (6/2) [ 2a + 5d ] = 42 or 2a+5d = 14 ...................(1)
from eqn.(1), if we substitute a = d, then we get a = 2
13th term = 2+12(2) = 26
Answered by Expert
21st January 2019,
7:46 AM
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