In an AP if a = 5 and d = 3 then what is the sum of first 20 terms?
AP में a = 5 और d = 3 हो तो पहले 20 पदों का योग कितना होगा?
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Correct Answer
B. 670 / 670
ExplanationStep 1: Use AP sum formula Sn = n/2[2a + (n-1)d]. Step 2: S20 = 10[10 + 57] = 670. Step 3: Remember the difference between n and n-1 in AP sum.
Step 1: AP sum formula Sn = n/2[2a + (n-1)d] लगाएं। Step 2: S20 = 10[10 + 57] = 670। Step 3: AP sum में n और n-1 का फर्क याद रखें।