Question

The first term of an arithmetic series is 2 and the sum of the first 15 terms is 292.5. Find the common difference.

Answer 1

$hey \: mate \: here \: is \: ur \: 2nd \: ans \\ \\ solution \\ \\ as \: given \\ \\ a = 800 \\ \\ d = 25 \\ \\ an = 5700 \\ \\ \\ \\ now \\ \\ from \: the \: formula \: of \: \\ \\ an = a + (n - 1)d \\ \\ = > 5700 = 800 + (n - 1)25 \\ \\ = > 5700 = 800 + 25n - 25 \\ \\ = > 5700 = 800 - 25 + 25n \\ \\ = > 5700 = 775 + 25n \\ \\ = > 25n = 5700 - 775 \\ \\ = > n = 4925 \div 25 \\ \\ = > n = 197 \: hours \\ \\ n \\ \\ \\ i \: hope \: that \: it \: will \: help \: u$