If the ${n^{th}}$ term of an $A.P.$ be $(2n - 1)$, then the sum of its first $n$ terms will be
${n^2} - 1$
${(2n - 1)^2}$
${n^2}$
${n^2} + 1$
The sum of the first and third term of an arithmetic progression is $12$ and the product of first and second term is $24$, then first term is
Let the digits $a, b, c$ be in $A.P.$ Nine-digit numbers are to be formed using each of these three digits thrice such that three consecutive digits are in $A.P.$ at least once. How many such numbers can be formed?
A number is the reciprocal of the other. If the arithmetic mean of the two numbers be $\frac{{13}}{{12}}$, then the numbers are
Which of the following sequence is an arithmetic sequence
What is the sum of all two digit numbers which give a remainder of $4$ when divided by $6$ ?