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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