Question

In the sequence {1}, {2,3}, {4,5,6}, {7, 8, 9,10}, .... of sets, the sum of the elements in 50th set is (a) 62525 (b) 65255 (c) 56255 (d) 55625

Answer 1

Step-by-step explanation:

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

• Given sequence we need to find the sum of elements in 50th set.
• So we have 1 + (2 + 3) + (4 + 5 + 6) + (7 + 8 + 9 + 10) +……….
• Now we have 1 + 2 + 3 + 4 and so on up to 49 and we need to find the sum of 49 terms
• We have sum = n(n + 1) / 2
•                        = 49 (49 + 1) / 2
•                       = 49 x 25
•                        = 1225
• So the series will be
•                   1226 + 1227 +…………….+ 1275)
• Now this is an A.P,
• So number of terms n = 50, first term a = 1226
• So we have Sn = n / 2 (a + l)
•                          = 50 / 2 (1226 + 1275)
•                          = 25 (2501)
•                          = 62,525

Reference link will be

https://brainly.in/question/12120155