ARITHMETIIC PROGRESSIONS

Asked by MANOJKUMAR | 15th May, 2010, 01:33: PM

Expert Answer:

S11 = 11(2a0 + 10d)/2 = 17

2a0 + 10d = 34/11                 ... (1)

S17 = 17(2a0 + 16d)/2 = 11

2a0 + 16d = 22/17                 ... (2)

Solving  (1) and (2) for a0 and d,

d = -56/187 and a0 = 2899/2057.

S28 = 28(2(2899/2057) + 27(-56/187))/2

Regards,

Team,

TopperLearning.

 

Answered by  | 17th May, 2010, 11:40: AM

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