The first term of an A.P. is 5, the last term is 45 and the sum of all its terms is 400. Find the number of terms and the common difference. The first term of an A.P. is 5 the last term is 45 and the sum of all its terms is 400. Find the number of terms and the common difference. October 4, 2020 Category: Chapter 5 - Arithmetic Progressions , Maths , NCERT Class 10 , Facebook Messenger WhatsApp Share this:TwitterFacebook Related