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If the 8th term of an AP is 31 and the 15th term is 16 more than the 11th term, find the AP. |
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Answer» Let a be the first term and d be the common difference of the AP. General term of an A.P. ⇒ an=a+(n−1)d We have, a8=31 and a15=16+a11 ⟹a+7d=31 and a+14d=16+a+10d ⟹a+7d=31 and 4d=16 ⟹a+7d=31 and d=4 ⟹a+7×4=31 ⟹a+28=31 ⟹a=3 Hence, the AP is a,a+d,a+2d,a+3d ... i.e.,3, 7, 11, 15, 19, ... |
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