is 78 atom of the AP 5 11 17 23

Answer: No, 78 is not a term of the AP 5,11,17,23,…5, 11, 17, 23, \ldots

Step-by-step solution

Step 1: Identify the first term and common difference

From the given Arithmetic Progression 5,11,17,23,…5, 11, 17, 23, \ldots, the first term is a=5a = 5. We find the common difference by subtracting the first term from the second term, giving d=11−5=6d = 11 - 5 = 6.

Step 2: Set up the equation for the nn -th term

Assume that 78 is the nn -th term of this AP, so an=78a_n = 78. We substitute a=5a = 5 and d=6d = 6 into the general formula an=a+(n−1)da_n = a + (n - 1)d.

Step 3: Solve for nn

Expanding the equation gives 78=6n−178 = 6n - 1. Adding 1 to both sides gives 6n=796n = 79, which leads to n=796n = \frac{79}{6}.

Step 4: Conclude whether 78 is a term

The term number nn must be a positive integer. Since 796\frac{79}{6} is not a natural number, 78 cannot be a term of the given AP.

Solve your own maths question free →