Advertisements
Advertisements
प्रश्न
Find the middle term of the A.P. 213, 205, 197, ---, 37.
उत्तर
Here,
a = 213
d = 205−213 = −8
Let the number of terms in the given AP be n.
We know
an=a+(n−1)d
⇒37=213+(n−1)(−8)
⇒8(n−1)=176
⇒n−1=22
⇒n=23
Thus, there are 23 terms in the given AP.
So, the (`(23+1)/2`)th term, i.e. the 12th term, will be the middle term.
∴ a12=213+(12−1)(−8)
⇒a12=213−88
⇒a12=125
Thus, 125 is the middle term of the given AP
APPEARS IN
संबंधित प्रश्न
A farmer borrows Rs.1,000 and agrees to repay with a total interest of Rs. 140 in 12 installments, each installment being less that the preceding installment by Rs. 10. What should be his first installment?
An arithmetic progression 5, 12, 19, …. has 50 terms. Find its last term. Hence find the sum of its last 15 terms.
The sum of the 2nd and the 7th terms of an AP is 30. If its 15th term is 1 less than twice its 8th term, find the AP.
is the Consider the expression an = 1 + n + n2, AP .a
How many three digit numbers are divisible by 7?
Find the middle term of the A.P. 213, 205, 197, ...., 37.
In the winter season let us take the temperature of Ooty from Monday to Friday to be in A.P. The sum of temperatures from Monday to Wednesday is 0°C and the sum of the temperatures from Wednesday to Friday is 18°C. Find the temperature on each of the five days.
If 6 times of 6th term of an A.P. is equal to 7 times the 7th term, then the 13th term of the A.P. is
Which of the following form an AP? Justify your answer.
`1/2, 1/3, 1/4, ...`
The eighth term of an AP is half its second term and the eleventh term exceeds one third of its fourth term by 1. Find the 15th term.
