JEE Main 2019 Mathematics question

MathematicsSequence and SeriesJEE Main 2019

Let be an A.P., and . If and S − 2T = 75, then is equal to:

Answer: (C)

Solution

S − 2T = 15d = 75 ⇒ d = 5; a = 7; .

Question ID VK-010093