Question

How many terms of the A.P. 16, 14, 12, are needed to give the sum 60? Explain .... why do we get two answers.​

Answer 1

Answer:

5 and 12 terms

Step-by-step explanation:

16,14,12,10,8,6,4,2,0,-2,-4,-6

The above are the first twelve terms .The last three positive terms approaching zero are equal to the first three negative terms from zero hence when summing the first twelve terms the three positive and negative terms cancels out therefore the effect is equal to that of the remaining positive 5 terms hence both 5 and 12 terms would result to a summation of 60.i feel that would the reason for two answers.

Answer 2

Answer:

n=5 or 12. Here, we get 2 answers because of a quadratic equation giving both +ve values.