Advertisements
Advertisements
प्रश्न
An article can be bought by paying Rs. 28,000 at once or by making 12 monthly installments. If the first installment paid is Rs. 3,000 and every other installment is Rs. 100 less than the previous one, find:
- amount of installments paid in the 9th month.
- total amount paid in the installment scheme.
Advertisements
उत्तर
Number of installments = n = 12
First installment = a = Rs. 3000
Depreciation in installment = d = –100
i Amount of installment paid in the 9th month
= t9
= a + 8d
= 3000 + 8 × (–100)
= 3000 – 800
= Rs. 2200
ii. Total amount paid in the installment scheme
= S12
= `12/2 [2 xx 3000 + 11 xx (-100)]`
= 6[6000 – 1100]
= 6 × 4900
= Rs. 29,400
संबंधित प्रश्न
If the sum of first 7 terms of an A.P. is 49 and that of its first 17 terms is 289, find the sum of first n terms of the A.P.
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)]
The nth term of an AP is given by (−4n + 15). Find the sum of first 20 terms of this AP?
The 9th term of an A.P. is equal to 6 times its second term. If its 5th term is 22, find the A.P.
Obtain the sum of the first 56 terms of an A.P. whose 18th and 39th terms are 52 and 148 respectively.
Find second and third terms of an A.P. whose first term is – 2 and the common difference is – 2.
Write the formula of the sum of first n terms for an A.P.
Solve the equation
– 4 + (–1) + 2 + ... + x = 437
Find the value of a25 – a15 for the AP: 6, 9, 12, 15, ………..
The nth term of an A.P. is 6n + 4. The sum of its first 2 terms is ______.
