math words and definitions

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Let a=first term, d = common difference, l=t n =last term, s = required sum. Then, Writing the series in the reverse order, Adding together the two series, ..

Let a = First term, r = common ratio, n = number of terms. Multiply both sides of (i) by r, the common ratio. Subtracting (ii) from (i), we get ..

A sequence of numbers is said to form a harmonic progression if their reciprocals form an arithmetic progressio..

n t h term of (1,2,3,....) is n Subtracting (ii) from (i), we get ..

Question 1 - Question: Find n. Answer: ..

Question: Answer: i) ii) iii) ..

Question: Find n if P(n,4) = 20P(n,2) Answer: ..

Question: A candidate is required to answer 6 out of 10 questions, which are divided into two groups, each containing 5 questions, and he is not permitted to attempt more than 4 from each group. In how many ways can he make his choice? Answer: ..