This sequence forms an A.P with common difference 1
Therefore, an = a + (n - 1)d
Where, an = nth term
a = first term
n = number of terms
d = common difference
Applying the formula, we get,
110 = 61 + (n - 1)
n = 50
Therefore, Sn = n (a + l)/2
Where, Sn = sum of nth terms
n = number of terms
a = first term
l = last term
Now, applying the formula and obtain the sum
S = 50(61 + 110)/2
S = (50 × 171)/2
S = 4275