The first and last terms of an A.P. are 18 and 48. If the sum of its terms is 396, then the number of terms will be?
12
To find the number of terms in an arithmetic progression (A.P.) with a given first term, last term, and sum, we use the formula for the sum of an A.P.:
Sn = n/2 × (a + l)
Where:
a = first term = 18
l = last term = 48
Sn = sum of n terms = 396
Substituting the values, we have:
396 = n/2 × (18 + 48)
This simplifies to:
396 = n/2 × 66
Multiplying both sides by 2 gives:
792 = 66n
To find n, divide both sides by 66:
n = 792/66 = 12
Therefore, the number of terms in the A.P. is 12.
Important Questions from Arithmetic Progression
What is the arithmetic mean of first 8 multiples of 13?
The average of five consecutive odd natural numbers is 27. The product of the first and fifth number is:
Find the sum of all the numbers between 100 to 200 which are divisible by 12.
In a garden, there are 6 daisy plants the first year. Each year, a gardener adds 3 new daisy plants the first year and loses 2 each year. He has 26 jasmine plants the first year and loses 2 each year. When will the number of daisy plants equal the number of jasmine plants after the first year?
If 23rd and 24th terms of an A.P. be 42 and 312 respectively, then its 37th term is:
