The 4th term of an A.P. is 22 and 7th term is 28. What is the common difference?
Correct: A
We know that the nth term of an A.P. is given by the formula: an = a + (n-1)d, where a is the first term and d is the common difference. Given the 4th term is 22 and the 7th term is 28, we can write two equations: a + 3d = 22 and a + 6d = 28. Subtracting the first equation from the second equation gives 3d = 6, which simplifies to d = 2.