Advertisements
Advertisements
Question
If 7 times the seventh term of the AP is equal to 5 times the fifth term, then find the value of its 12th term.
Advertisements
Solution
7(a + 6d) = 5(a + 4d)
⇒ 2a + 22d = 0
⇒ a + 11d = 0
⇒ t12 = 0
APPEARS IN
RELATED QUESTIONS
A small terrace at a football field comprises 15 steps, each of which is 50 m long and built of solid concrete. Each step has a rise of `1/4` m and a tread of `1/2` m (See figure). Calculate the total volume of concrete required to build the terrace.
[Hint: Volume of concrete required to build the first step = `1/4 xx 1/2 xx 50 m^3`]
Three numbers are in A.P. If the sum of these numbers is 27 and the product 648, find the numbers.
Find the three numbers in AP whose sum is 15 and product is 80.
The sum of first n terms of an A.P. is 3n2 + 4n. Find the 25th term of this A.P.
Suppose three parts of 207 are (a − d), a , (a + d) such that , (a + d) >a > (a − d).
The term A.P is 8, 10, 12, 14,...., 126 . find A.P.
Find the common difference of an A.P. whose first term is 5 and the sum of first four terms is half the sum of next four terms.
Find the sum of odd natural numbers from 1 to 101
Solve the equation:
– 4 + (–1) + 2 + 5 + ... + x = 437
