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The first term and the common difference...

The first term and the common difference of an A.P. are 10 and 5 respectively. Complete the following activity to find the sum of the first 30 terms of the A.P.
`S_(n) = ( n )/(2) [ square + ( n -1) d ]`
`:. S_(30) = (30)/(2) [ 20 + ( 30-1) xx square ]`
`= 15 [ 20 + square ]`
` = 15 xx 165 `
` = square `

Text Solution

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The correct Answer is:
2a,5,145,2475
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