B = 1/1.2.3.4 + 1/2.3.4.5 + 1/3.4.5.6 + ... + 1/27.28.29.30
= 1/3.(1/1.2.3 − 1/2.3.4 + 1/2.3.4 − 1/3.4.5 + ... + 1/27.28.29 − 1/28.29.30)
= 1/3.(1/1.2.3 − 1/28.29.30) = 1353/8120

5+[-(-12)+(-9)]-[7-(-10)+3]= -12

II. 
1. A
2. D
3. A
4. A
5. D
III.
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