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What is the sum of all the multiples of 5 greater than 50 but less than 200? |
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Answer» First multiple after 50 = 55 Last multiple before 200 = 195 therefore, a = 55, d = 5 an = 195 => 55+(n-1)5 = 195 (n-1)5 = 195-55 (n-1)5 = 140 (n-1) = 140/5 n = 28+1 = 29 therefore, S29 = 29/2 x (55+195) S29 = 29x250/2 S29 = 29X125 S29 = 3625 Hence, the sum of all the multiples of 5 greater than 50 but less than 200 is 3625 |
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