Elitmus
Exam
Numerical Ability
Geometry
is perimeter of trianglr> 30? .a,b,c are sides of triangle.
a. a-b=15;
b. area of triangle =50;
Read Solution (Total 2)
-
- answer is (A)
statement 1: a-b=15
=> a = b + 15 and a + b >=15(if b = 0)
in a triangle the sum of two sides is always greater than the third
=> b + c > a
=>b+c > b + 15
=>c > 15
perimeter = (a + b) + c
>30(since both terms are greater than 15.
statement 2: area of triangle = 50
area of a triangle is maximum when all the edges are equal i.e. an equilateral triangle
suppose perimeter = 30, therefore edge = 30
therefore area = ((3**1/2)/4)*(edge**2)
= 1.79*25
= 43
but it is given the area is 50 so this statement is wrong. - 7 years agoHelpfull: Yes(4) No(5)
- Taking 1st condition..... a-b = 15, we know that difference between any two sides of a triangle is smaller than the the 3rd side.
it means that 3rd side will be greater than 15.
i.e. a+b+c = 15+(15 + something ) > 30
So, Statement 1 is sufficient to give answer of the question.
Now taking 2nd statement......Since it is not given what type of triangle it is asking...so 2nd statement is not Sufficient to give the answer. - 7 years agoHelpfull: Yes(0) No(2)
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