Elitmus
Exam
Logical Reasoning
Decision Making and Problem Solving
there may be mistake in the qes. not sure.
(a-b)^2=1 & (a+b)^2=25
values of a,b?
i)a is a prime no
ii)a<2
Read Solution (Total 10)
-
- atq
value of
set(a,b)={(-2,-3),(3,-2),(-3,2),(2,3)}
frm 1stmnt
some value is prime and some is nt..but a should have unique value.
so i cant satisfied
frm stmnt 2
not all value of a - 10 years agoHelpfull: Yes(4) No(2)
- i is true.
- 10 years agoHelpfull: Yes(1) No(1)
- (a-b)^2=a2-2ab+b2=1
a2+b2=1+2ab;...........................(1)
also, (a+b)^2=a2+2ab+b2=25
a2+b2=25-2ab..........................(2)
frm (1)& (2)
ab=6
so ab can be (1,6) , (6,1) ,(2,3) ,(3,2) and also its -ve values
case 1:- a is prime
1 is neither a prime nor composite no and -ve no cannot be prime and also 6 is not a prime no, hence we r left with options (2,3) ,(3,2) but we dn't have clear values for a and b
case 2: - a - 10 years agoHelpfull: Yes(1) No(1)
- with i ans can find
- 10 years agoHelpfull: Yes(0) No(1)
- second condition is:
|a|>2 - 10 years agoHelpfull: Yes(0) No(0)
- both statements are necessary
(a-b)^2=(b-a)^2 - 10 years agoHelpfull: Yes(0) No(0)
- (a, b)=(2,3), (3,2), (-2,-3), (-3,-2)
1) a is prime
(3,2) (-3,-2)
2) a - 10 years agoHelpfull: Yes(0) No(0)
- a-b=1
a+b=5
by solving answer for a=3
so its a prime
i is trye - 10 years agoHelpfull: Yes(0) No(0)
- (a) If a is prime no. it cannot be -ve
no. could be (2,3) & (3,2)
becoz (2-3)^2=1 & (2+3)^2=25 similarly for (3,2)
since there are two option we cannot find the value of a,b specifically
(b) since only possible values are (2,3) & (3,2)
so a - 9 years agoHelpfull: Yes(0) No(0)
- It's answer should be (-2,-3) and satisfied to both conditions
- 9 years agoHelpfull: Yes(0) No(0)
Elitmus Other Question