Advertisements
Advertisements
प्रश्न
Complete the following activity to find the 19th term of an A.P. 7, 13, 19, 25, ........ :
Activity:
Given A.P. : 7, 13, 19, 25, ..........
Here first term a = 7; t19 = ?
tn + a + `(square)`d .........(formula)
∴ t19 = 7 + (19 – 1) `square`
∴ t19 = 7 + `square`
∴ t19 = `square`
Advertisements
उत्तर
Given, A.P. : 7, 13, 19, 25, ..........
Here, first term a = 7; t19 = ?
tn + a + (n – 1)d .........(formula)
∴ t19 = 7 + (19 – 1)6
∴ t19 = 7 + 108
∴ t19 = 115
APPEARS IN
संबंधित प्रश्न
If the ratio of the sum of first n terms of two A.P’s is (7n +1): (4n + 27), find the ratio of their mth terms.
Ramkali required Rs 2,500 after 12 weeks to send her daughter to school. She saved Rs 100 in the first week and increased her weekly saving by Rs 20 every week. Find whether she will be able to send her daughter to school after 12 weeks.
What value is generated in the above situation?
Find four numbers in A.P. whose sum is 20 and the sum of whose squares is 120
Check whether -150 is a term of the A.P. 11, 8, 5, 2, ....
Find the sum given below:
34 + 32 + 30 + ... + 10
In an AP given l = 28, S = 144, and there are total 9 terms. Find a.
A sum of Rs 700 is to be used to give seven cash prizes to students of a school for their overall academic performance. If each prize is Rs 20 less than its preceding prize, find the value of each of the prizes.
The first and last terms of an AP are a and l respectively. Show that the sum of the nth term from the beginning and the nth term form the end is (a + l).
How many two-digit numbers are divisible by 6?
How many two-digits numbers are divisible by 3?
The sum of the first n terms of an AP is `((3n^2)/2 + (5n)/2)`. Find its nth term and the 25th term.
There are 25 rows of seats in an auditorium. The first row is of 20 seats, the second of 22 seats, the third of 24 seats, and so on. How many chairs are there in the 21st row ?
In an A.P., the sum of first ten terms is −150 and the sum of its next ten terms is −550. Find the A.P.
If the sum of n terms of an A.P. be 3n2 + n and its common difference is 6, then its first term is ______.
If the sum of n terms of an A.P. is 3n2 + 5n then which of its terms is 164?
The 9th term of an A.P. is 449 and 449th term is 9. The term which is equal to zero is
The common difference of an A.P., the sum of whose n terms is Sn, is
Q.19
The sum of first n terms of an A.P. whose first term is 8 and the common difference is 20 equal to the sum of first 2n terms of another A.P. whose first term is – 30 and the common difference is 8. Find n.
First four terms of the sequence an = 2n + 3 are ______.
