Advertisements
Advertisements
प्रश्न
Choose the correct alternative answer for the following question .
What is the sum of the first 30 natural numbers ?
पर्याय
464
465
462
461
Advertisements
उत्तर
The given series is 1 + 2 + 3 + ... + 30
Here,
a = 1
d = 1
n = 30
\[S_n = \frac{n}{2}\left( 2a + \left( n - 1 \right)d \right)\]
\[ S_{30} = \frac{30}{2}\left( 2a + \left( 30 - 1 \right)d \right)\]
\[ = \frac{30}{2}\left( 2\left( 1 \right) + 29\left( 1 \right) \right)\]
\[ = 15\left( 2 + 29 \right)\]
\[ = 15 \times 31\]
\[ = 465\]
APPEARS IN
संबंधित प्रश्न
The sum of three numbers in A.P. is –3, and their product is 8. Find the numbers
Find the sum of the first 25 terms of an A.P. whose nth term is given by an = 7 − 3n
Find the sum of all multiples of 7 lying between 300 and 700.
Is –150 a term of the AP 11, 8, 5, 2, ...?
The angles of a quadrilateral are in AP whose common difference is 10°. Find the angles.
How many three-digit natural numbers are divisible by 9?
The sum of the first n terms of an AP is (3n2 + 6n). Find the nth term and the 15th term of this AP.
Write the nth term of an A.P. the sum of whose n terms is Sn.
Q.5
Find whether 55 is a term of the A.P. 7, 10, 13,... or not. If yes, find which term is it.
The sum of all two digit odd numbers is ______.
The sum of first five multiples of 3 is ______.
Which term of the AP: –2, –7, –12,... will be –77? Find the sum of this AP upto the term –77.
If Sn denotes the sum of first n terms of an AP, prove that S12 = 3(S8 – S4)
Find the sum of first 17 terms of an AP whose 4th and 9th terms are –15 and –30 respectively.
Sum of 1 to n natural number is 45, then find the value of n.
In the month of April to June 2022, the exports of passenger cars from India increased by 26% in the corresponding quarter of 2021-22, as per a report. A car manufacturing company planned to produce 1800 cars in 4th year and 2600 cars in 8th year. Assuming that the production increases uniformly by a fixed number every year. |
Based on the above information answer the following questions.
- Find the production in the 1st year
- Find the production in the 12th year.
- Find the total production in first 10 years.
[OR]
In how many years will the total production reach 31200 cars?
Three numbers in A.P. have the sum of 30. What is its middle term?
The sum of 41 terms of an A.P. with middle term 40 is ______.
