Question

9. The sum of n terms of an A.P whose first term is 5 and the common difference is 36 is equal
to the sum of two n terms of another A.P whose first term is so
p whose first term is 36 and the common difference is
5. Find n
10. Find the sum of indicated number of terms of the following A.Ps:
01- -.1-5, 1-3, ....... to n terms.
ii. 8, 3, -2.......upto 22 terms
how many terms of of the AP: 24, 21, 18, .......must be taken so that their sum is 78?
12. Find the sum of all the two-digit numbers which when divided by 7 leave a remainder 1.
o times of the 8th term of an AP is equal to 13 times of the 13th term, show that 21 st term
of an AP is zero
14. Find the sum of all two digit numbers.
15. The 3rd term of a GP is 4. Find the product of its first 5 terms.
16. Find the 8th term of the geometric progression : 5,10,20...
17. The product of 3rd and 8th terms of G.P is 243. If its 4th term is 3, find its 7th.
18. How many terms of the geometric progression 1+ 4 + 16 +64 + .....must be added to get
sum equal to 5461?
19. A GP has c.r=3 and last term 486.If the sum of its terms is 728, find its first term.
20. Find the geometric mean between 14 and
(geometric mean between a, b is Vab)​

Answer 1

Answer:

solution of question 9 and 12