Ask Questions, Get Answers
Menu
X
JEEMAIN Crash Practice
15 Test Series
NEET Crash Practice
15 Test Series
CBSE XII
Math
JEEMAIN
Math
Physics
Chemistry
Practice Test Series
CBSE XI
Math
NEET
Physics
Chemistry
Biology - XII
Biology - XI
Olympiad class V
Math - 5 Test Series
Olympiad class VI
Math - 5 Test Series
studyplans
JEEMAIN Crash Practice
15 Test Series
NEET Crash Practice
15 Test Series
CBSE XII
Math
JEEMAIN
Math
Physics
Chemistry
Practice Test Series
CBSE XI
Math
NEET
Physics
Chemistry
Biology - XII
Biology - XI
Olympiad class V
Math - 5 Test Series
Olympiad class VI
Math - 5 Test Series
mobile
exams
ask
sample papers
tutors
pricing
login
X
ASK
Home
>>
JEEMAIN and NEET
>>
Mathematics
>>
Class11
>>
Permutations and Combinations
The no. of rectangles in a chess board is ?
$\begin{array}{1 1} 64 \\ 648 \\ 1296 \\ 2592 \end{array}$
jeemain
math
class11
ch7
permutations-and-combinations
combinations
easy
Share
asked
Aug 27, 2013
by
rvidyagovindarajan_1
edited
Apr 5, 2016
by
meena.p
Please
log in
or
register
to add a comment.
Please
log in
or
register
to answer this question.
1 Answer
In a chess board there are 9 vertical lines and 9 horizontal lines.
To form a rectangle we need 2 vertical lines and two horizontal lines at a time.
$\therefore $ Total no. of rectangles = $^9C_2.^9C_2=36\times36=1296$
answered
Aug 27, 2013
by
rvidyagovindarajan_1
edited
Dec 20, 2013
by
meenakshi.p
Please
log in
or
register
to add a comment.
Related questions
Find the number of rectangles in the figure.
jeemain
math
class11
ch7
permutations-and-combinations
combinations
medium
asked
Aug 20, 2013
by
rvidyagovindarajan_1
1
answer
A Guide with 8 persons takes 3 at a time in a boat at a time as often as he can without taking the same 3 persons more than once. The no. of times each person will go in the boat is?
jeemain
math
class11
ch7
permutations-and-combinations
combinations
easy
asked
Sep 3, 2013
by
rvidyagovindarajan_1
1
answer
In how many ways can 7 plus (+) signs and 4 minus (-) signs can be arranged in a row so that no two minus signs are together?
jeemain
math
class11
ch7
permutations-and-combinations
combinations
easy
asked
Aug 20, 2013
by
rvidyagovindarajan_1
1
answer
A polygon has 44 diagonals. The no. of sides of the polygon = ?
jeemain
math
class11
ch7
permutations-and-combinations
combinations
easy
asked
Aug 13, 2013
by
rvidyagovindarajan_1
1
answer
The no. of diagonals of $n$ sided polygon =?
jeemain
math
class11
ch7
permutations-and-combinations
combinations
easy
asked
Aug 13, 2013
by
rvidyagovindarajan_1
1
answer
Four couples (husband and wife) decide to form a committee of 4 members. How many ways this can be done so that no couple finds a place.
jeemain
math
class11
ch7
permutations-and-combinations
combinations
easy
asked
Aug 11, 2013
by
rvidyagovindarajan_1
1
answer
There are two urns. Urn A has 3 distinct red balls and Urn B has 9 distinct blue balls. From each urn two balls are drawn at random and then transfered to other. The no. of ways in which this can be done is?
jeemain
math
class11
ch7
permutations-and-combinations
combinations
easy
asked
Aug 9, 2013
by
rvidyagovindarajan_1
1
answer
Ask Question
Tag:
Math
Phy
Chem
Bio
Other
SUBMIT QUESTION
►
Please Wait
Take Test
JEEMAIN Crash Practice
15 Test Series
NEET Crash Practice
15 Test Series
JEEMAIN
350+ TESTS
NEET
320+ TESTS
CBSE XI MATH
50+ TESTS
CBSE XII MATH
80+ TESTS
...
X