Question

If $\frac{1}{(1+d)(1+2d)}+\frac{1}{(1+2d)(1+3d)}+...+\frac{1}{(1+9d)(1+10d)}=1,$ then the value of 50d is____. (d > 0)

• A. 50
• B. 60
• C. 25
• D. 30

Answer 1

Answer: (C)

25

Answer 2

The Correct answer is option is (C) : 25