Advertisements
Advertisements
प्रश्न
If the ratio of the sum of the first n terms of two A.Ps is (7n + 1) : (4n + 27), then find the ratio of their 9th terms.
Advertisements
उत्तर
Suppose a1, a2 be the first terms and d1, d2 be the common differences of the two given A.Ps.
Then the sums of their n terms are
APPEARS IN
संबंधित प्रश्न
In an AP given a3 = 15, S10 = 125, find d and a10.
In a potato race, a bucket is placed at the starting point, which is 5 m from the first potato and other potatoes are placed 3 m apart in a straight line. There are ten potatoes in the line.
A competitor starts from the bucket, picks up the nearest potato, runs back with it, drops it in the bucket, runs back to pick up the next potato, runs to the bucket to drop it in, and she continues in the same way until all the potatoes are in the bucket. What is the total distance the competitor has to run?
[Hint: to pick up the first potato and the second potato, the total distance (in metres) run by a competitor is 2 × 5 + 2 ×(5 + 3)]
Find the sum of the following arithmetic progressions:
3, 9/2, 6, 15/2, ... to 25 terms
The first three terms of an AP are respectively (3y – 1), (3y + 5) and (5y + 1), find the value of y .
The fourth term of an A.P. is 11. The sum of the fifth and seventh terms of the A.P. is 34. Find its common difference.
The sum of first n odd natural numbers is ______.
The sum of the first three numbers in an Arithmetic Progression is 18. If the product of the first and the third term is 5 times the common difference, find the three numbers.
Solve for x: 1 + 4 + 7 + 10 + ... + x = 287.
A merchant borrows ₹ 1000 and agrees to repay its interest ₹ 140 with principal in 12 monthly instalments. Each instalment being less than the preceding one by ₹ 10. Find the amount of the first instalment
The sum of the first 15 multiples of 8 is ______.
