Example 14 - Find sum of (i) first 1000 positive integers

Example 14 - Chapter 5 Class 10 Arithmetic Progressions - Part 2

Example 14 - Chapter 5 Class 10 Arithmetic Progressions - Part 3 Example 14 - Chapter 5 Class 10 Arithmetic Progressions - Part 4

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Example 14 (Method 1) Find the sum of the first 1000 positive integers Positive integers start from 1 First 1000 positive integers are 1, 2, 3, 4, ………., 1000 This is an AP with First term = a = 1 Common Difference = d = 1 Number of terms = n = (1000 − 1) + 1 = 1000 To find sum, we use the formula Sum = 𝒏/𝟐[𝟐𝒂+(𝒏−𝟏)𝒅] Putting values Sum = 1000/2[2 × 1+(1000−1)(1)] Sum = 1000/2[2+999] Sum = 500 × 1001 Sum = 500500 Example 14 (Method 2) Find the sum of the first 1000 positive integers Positive integers start from 1 First 1000 positive integers are 1, 2, 3, 4, ………., 1000 This is an AP with First term = a = 1 Common Difference = d = 1 Number of terms = n = (1000 − 1) + 1 = 1000 Last term = l = 1000 To find sum, we use the formula Sum = 𝒏/𝟐[𝒂+𝒍] Putting values Sum = 1000/2[1+1000] Sum = 500 × 1001 Sum = 500500

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Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 13 years. He provides courses for Maths, Science, Social Science, Physics, Chemistry, Computer Science at Teachoo.