MCQ
Find the sum of series 62 + 72 +…………………..+ 152.
- A55
- B1185
- C1240
- D1385
✓
Answer
- 1185
Solution:
62 + 72 +………………..….. + 152
= (12 + 22 + 32 + …….. +152) – (12 + 22 + 32 + 42 + 52)
$=\frac{15\times16\times31}{6}-\frac{5\times6\times11}{6}$
$=1240-55=1185.$
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