Elitmus
Exam
Numerical Ability
Averages
Number of rectangles which has the same area and perimeter?
A) only one
B) only 2
C) more than 2
D) None of the above
Read Solution (Total 10)
-
- The Correct option is: (C) more than 2
Possibilities-
1. If height=3 & width=6
2. If height=4 & width=4
3. If height=2.5 & width=10
..........................
etc. etc. - 8 years agoHelpfull: Yes(30) No(3)
- option c is correct
area = perimeter
l*b=2(l+b)
l . b =2l +2b ( convert l or b in term of others ( b , l ) )
l.b-2l=2b
l (b-2) =2b
therefore l = 2b/b-2 for all b > 2 and for rectangle l != b
it is clear that for many value of b there exist l
for ex
b=3 ,l = 6
b=5 ,l=10/3
b=6 ,l=3
b=7,l=2.8
etc - 8 years agoHelpfull: Yes(8) No(1)
- Only 1.
Coz 8x3=6x4=24
Here area equal but perimeter diff i.e 22 and 20. So ans is 1 - 8 years agoHelpfull: Yes(3) No(5)
- Ans - (C). How?
Let the length and breadth of the rectangle be l and b respectively. So, we need to solve the equation:
2*(l + b) = l*b, which gives:
l = 2b/(b-2)
Since, l > 0 and b > 0, b >2.
Also, since l and b need not necessarily be integers, substitute different values of b to get different values of l. - 8 years agoHelpfull: Yes(3) No(1)
- Ans is c
L*b= 2(l+b)
Lb-2l=2b
L=2b/(b-2)
So we can take any value of b greater than 2, for which we get the length such that area and perimeter becomes equal - 8 years agoHelpfull: Yes(1) No(0)
- which one is correct?
- 8 years agoHelpfull: Yes(0) No(0)
- B)
front 2 face - 8 years agoHelpfull: Yes(0) No(0)
- Number of rectangles which has the same area and perimeter?( take square as a rectangle and case of rectangle will be counted as 1 case only eg (4,2) and (2,4) as same case)
ans will be only 2
there will be two case one will be square it self where one will be rectangle - 8 years agoHelpfull: Yes(0) No(0)
- ans =b
example if breadth=2 , length=3 and breadth =3 ,length=2 it has same area and perimeter
if u take anything rather than that the length and perimeter is different - 8 years agoHelpfull: Yes(0) No(0)
- ans is b.
interchange the length and breadth of rectangle you will get two rectangles which have same area and perimeter. - 8 years agoHelpfull: Yes(0) No(0)
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