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Question What will be the difference between two successive sums for-
(a) 5 consecutive numbers
1 + 2 + 3 + 4 + 5 = 15
2 + 3 + 4 + 5 + 6 = 20
3 + 4 + 5 + 6 + 7 = 25
Difference between two successive sums:
20 – 15 = 25 – 20 = 5
So, the difference is 5.
(b) 6 consecutive numbers
Solution:
1 + 2 + 3 + 4 + 5 + 6 = 21
2 + 3 + 4 + 5 + 6 + 7 = 27
3 + 4 + 5 + 6 + 7 + 8 = 33
Difference between two successive sums:
27 – 21 = 33 – 27 = 39 – 33 = 6.
So, the difference is 6.
Find the following sums without adding the numbers directly.
(a) 67 + 68 + 69
(b) 24 + 25 + 26+ 27
(c) 48 + 49 + 50 + 51 + 52
(d) 237 + 238 + 239 + 240 + 241 + 242
Solution:
NCERT Textbook Page 48
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