Question

In the sequence {1} . {2,3} , {4,5,6} , {7,8,9,10}, ...... of sets the sum of elements in the 50th set is

• A. 62525
• B. 65225
• C. 56255
• D. 55625

Answer 1

Answer: (A)

First term of 50th set is (1+2+3+....+49) +1 = 1226
Required some = 50/2 (2 $\times$ 1226 + 49 $\times$ 1 )= 6252