The sum of all even numbers from 2 to 100 as an AP whose first term is 2 and the common difference is 2. First find the number of terms between 2 and 100. For that. Tn = 100 = a + (n-1)d = 2 +(n-1)*2, or. 50 = 1+n-1 = n, SO Tn = 50. Sn = (n/2)[2a+(n-1)d] = (50/2)[2*2 + (50–1)*2]. = 25[4+98]. = 25*102. =2550. Answer. read more