Elitmus
Exam
Numerical Ability
Number System
In a triangle,A is greater than B and C. Sum of angles A and seven times of B is 155 . Then find the range of angle C
A.79<= c >25
B.79<= c =>31
C.81<= c >31
D.none of these
Read Solution (Total 13)
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- Sorry for the mistake...
Ans is B.
A+7B=155; A+B+C=180....
solve both...will get C=25+6B; Now for B=1; C=31 & A=148;
then max value of B for which both given condition satisfied...is B=9;
So for B=9; C=79 & A=92;
Hence range of angle C is 31 to 79... - 10 years agoHelpfull: Yes(16) No(2)
- Sorry guys for typing mistake, this one is CORRECT
Value of A is greater than B and C, and A+7B=155
When A=85, B=10, then (85+7*10=155) so here C=180-(85+10) = 180-95 = 85
When A=148, B=1, then (148+7*1=155), So here C = 180-(148+1) = 180-149 = 31
So, Range of C will be from 31 to 85. - 10 years agoHelpfull: Yes(8) No(8)
- Ans is C.
A+7B=155; A+B+C=180....
solve both...will get C=25+6B; Now for B=1; C=31 & A=148;
then max value of B for which both given condition satisfied...is B=9;
So for B=9; C=79 & A=92;
Hence range of angle C is 31 to 79... - 10 years agoHelpfull: Yes(4) No(1)
- the ans must be D. none of these
becoz in triangle A + B + C = 180
and when C=25 then A+B=155 or when c=31 then A+B=149
therefore the condiyion A+7B=155 is not satisfied.
it is not satisfid for other values of C as well... - 10 years agoHelpfull: Yes(2) No(1)
- Value of A is greater than B and C, and A+7B=155
When A=78, B=11 (85+10*7=155) so C=180-(85+10) = 180-95 = 85
When A=148, B=1 (148+7*1=155), So here C = 180-(148+1) = 180-149 = 31
So, Range of C will be from 31 to 85. - 10 years agoHelpfull: Yes(1) No(4)
- A+B+C=180,
A+7B=155
SO, A=155-7B
AND from (i) equation C=25+6B
now becoz A>C
so 155-7B>25+6B
130>13B
so B - 9 years agoHelpfull: Yes(1) No(0)
- C. 85 = 31
- 10 years agoHelpfull: Yes(0) No(2)
- at c=25 a and b equal but c cant be 0 to make triangle c >0 so solution a
- 10 years agoHelpfull: Yes(0) No(17)
- min is 31....bt how to find max value for c...?????
- 10 years agoHelpfull: Yes(0) No(0)
- A,because the sum of three angles in a triangle is 180 degree.Given A is greater than B and C and sum of A and C is 155.So, 180-155=25.
- 10 years agoHelpfull: Yes(0) No(0)
- answer must be A 7925
- 10 years agoHelpfull: Yes(0) No(0)
- A+7B=155 & A+B+C=180 Solving both we get=C=25+6B
For,B=1..C=25+6=31(min. value)
Now chosing C=81 from given options ,so as to check whether calculated value of A satisfy the condition A>B and A>C
C=81 we know,C=25+6B
81=25+6B,Thus B=9.33
A+7B=155 From here A=155-7(9.33)=89.69
We can Check the conditions A>B and A>C
Also,A+B+C ie..,89.69+9.33+81=180
Thus,option" c" is correct - 9 years agoHelpfull: Yes(0) No(0)
- Answer is B
A+7B=155
A+B+C=180
==>C=25 + 6B--------(1)
Now max value of A is when B=1.
so when B=1, A=148, c=31.
Now since A>C
A>25+6B (from 1)
155-7B>25+6B
on solving
B - 9 years agoHelpfull: Yes(0) No(0)
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