If 1500 seats are to be arranged in the auditorium, how many seats are still left to be put after 10th row?

 

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Transcript

Question 37 (ii) – Choice 2 If 1500 seats are to be arranged in the auditorium, how many seats are still left to be put after 10th row? We need to find how many seats are still left to be put after 10th row Thus, Seats left after 10th row = Total seats − Seats till 10th row = 1500 − S10 Finding S10 Now Sn = 𝑛/2 (2a + (n – 1)d) Putting n = 10, a = 30, d = 10 S10 = 𝟏𝟎/𝟐 (2 × 30 + (10 – 1) × 10) = 5 (60 + 9 × 10) = 5 (60 + 90) = 5 × 150 = 750 Now, Thus, Seats left after 10th row = 1500 − S10 = 1500 – 750 = 750

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Davneet Singh

Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 14 years. He provides courses for Maths, Science, Social Science, Physics, Chemistry, Computer Science at Teachoo.