Login
Remember
Register
Poraxali.com
Questions
Unanswered
Users
Ask a Question
Ask a Question
The sum of the first 12 terms of an A.P. is 900. If its first term is 20 then find the common difference and 12th term.
0
votes
1.1k
views
asked
Sep 7
in
Maths
by
Priya
(
33.3k
points)
The sum of the first 12 terms of an A.P. is 900. If its first term is 20 then find the common difference and 12th term.
cbse
class 10
Facebook
Twitter
Please
log in
or
register
to answer this question.
1
Answer
0
votes
answered
Sep 7
by
Haren
(
268k
points)
12/2 [2 × 20 + 11d] = 900
⇒ d = 10
Also a
12
= 20 + 11 × 10 = 130
Please
log in
or
register
to add a comment.
Related questions
0
votes
1
answer
1.2k
views
If △ABC∼△PQR such that 3AB = 2PQ and BC=10 cm, then length QR is equal to (A) 10 cm (B) 15 cm (C) 20 3cm (D) 30 cm
asked
Sep 7
in
Maths
by
Priya
(
33.3k
points)
cbse
class 10
0
votes
1
answer
241
views
The perimeter of sector OACB of the circle centred at O and of radius 24, is 73.12 cm. (i) Find the central angle ∠AOB
asked
Sep 8
in
Maths
by
Priya
(
33.3k
points)
cbse
class 10
0
votes
1
answer
72
views
The 4th term from the end of the A.P −8, −5, −2, … ,49 is (A) 37 (B) 40 (C) 1 (D) 43
asked
Sep 7
in
Maths
by
Priya
(
33.3k
points)
cbse
class 10
0
votes
1
answer
176
views
In the given figure, ∆ABC is an equilateral triangle. Coordinates of vertices A and B are (0,3) and (0,−3) respectively
asked
Sep 7
in
Maths
by
Priya
(
33.3k
points)
cbse
class 10
0
votes
1
answer
562
views
If perimeter of given triangle is 38 cm, then length AP is equal to (A)19 cm (B) 5 cm (C) 10 cm (D) 8 cm
asked
Sep 7
in
Maths
by
Priya
(
33.3k
points)
cbse
class 10
Categories
All categories
Biology
(74)
Science
(189)
Maths
(107)
English
(91)
Grammar
(92)
Education
(15)
Computer Science
(18)
Others
(31)
Economics
(23)
Geography
(27)
Social science
(73)
Business Studies
(15)
General Knowledge
(42)
History
(10)
...