Elitmus
Exam
Numerical Ability
Number System
if a, a+2, a+4 are prime numbers ,then the number of possible solutions for a is-
a. 1 b.2 c. 3 d. more than 3
Read Solution (Total 39)
-
- only on solution exist which is 3
- 10 years agoHelpfull: Yes(32) No(7)
- option:-a
3,5,7(only 1 case) - 10 years agoHelpfull: Yes(28) No(8)
- option ( b )
put a= 1, the combination will be 1,3,5
put a=3
the combination will be 3, 5,7
which r prime no.
- 10 years agoHelpfull: Yes(13) No(49)
- more than 3 is right answer
because
put a=1 no 1,3,5
put a=5 no 5,7,11
put a=11 no 11,13,17
put a=17 no 17,19,23 - 10 years agoHelpfull: Yes(9) No(104)
- Ans.1
(3,5,7) - 10 years agoHelpfull: Yes(7) No(3)
- ans is a)1 only a=3 will satisfy the condition of prime number.i.e, 3,5,7
- 10 years agoHelpfull: Yes(7) No(4)
- Ans= 1 becuz 1 is not a prime no .. so 3 , 5 ,7
- 10 years agoHelpfull: Yes(7) No(3)
- only one solution,put a=3 then we get 3,5,7
- 10 years agoHelpfull: Yes(4) No(0)
- only for a=1 or 3 so the answer is b
- 10 years agoHelpfull: Yes(4) No(5)
- option a=1
it will take only one value 3
3
3+2=5
3+4=7
(3,5,7) so answr is only one value will take - 10 years agoHelpfull: Yes(4) No(0)
- a a+2 a+4
put a=1,2,3....
at a=1: 1,3,5 (But 1 is not prime number it is a unique number )
at a=3: 3,5,7
at a=5: 5,7,9(Not prime number set)
.....
so,only 1 combination is possible..ans(a) - 9 years agoHelpfull: Yes(4) No(0)
- @Akhil Dhawan
1 is not a prime number => a=3 is the only possible solution - 10 years agoHelpfull: Yes(3) No(0)
- a=1 then 1,3,5
a=3 then 3,5,7
so the ans. will be (b). - 10 years agoHelpfull: Yes(2) No(11)
- only one solution i.e., 3
a=3
a+2=5
a+4=7 - 10 years agoHelpfull: Yes(2) No(0)
- Ans. is 1
Since 1 is not a prime no.
So take a=3 then a,a+2,a+4 = 3,5,7. - 9 years agoHelpfull: Yes(2) No(0)
- more than 3
5, 5+2=7 ,7+4=11
11,11+2=13,13+4=17
17,17+2=19,19+4=23,
41,41+2=43,43+4=47 - 9 years agoHelpfull: Yes(2) No(7)
- MORE THAN 3
If a=1, 1,3,5
If a=3, 3,5,7
If a=5, 5,7,9
-----------------
------------------
IF a=k, then ....... - 10 years agoHelpfull: Yes(1) No(13)
- let value of a = 3
then we get 3,5,7 which is prime so the possible solutns of a will be 3
- 9 years agoHelpfull: Yes(1) No(1)
- option a is correct as a=3 gives 3,5,7
- 10 years agoHelpfull: Yes(0) No(1)
- if a=1
the combinations will be (1,3,5)
if a=3
the combinations are(3,5,7) - 10 years agoHelpfull: Yes(0) No(4)
- a.1 bcz if a=3 then only a,a+2,a+4 exist
- 10 years agoHelpfull: Yes(0) No(0)
- Answer would be 3
the possible combinatins are:
5,7,11
11,13.17
and
17,19,23
- 10 years agoHelpfull: Yes(0) No(4)
- only one solution which is 3 , as there is only one possible combination 3,5,7
- 10 years agoHelpfull: Yes(0) No(0)
- Que is that how many possible value of a, which satisfy the condition...
a, a+2, a+4 will be prime.
if we take a=3
3, 5, 7 will be primes
if we take a=37
37, 39, 41 also primes values
then possible solution values of a is 3,37.
ans will be: b). 2 - 9 years agoHelpfull: Yes(0) No(8)
- Ans. is 2
If a=3 => 3,5,7
If a=11 => 11,13,17
- 9 years agoHelpfull: Yes(0) No(4)
- only solution exist which is 3 bcz prime no (expect 2,3 )are of form 6M+-1 if v take a =6M+1 ,a+2 will be 6M+3 which is divisible by 3 and if v take a=6M-1 ,a+4 will be 6M+3 which is divisible by 3 so only solution is 3,5,7 only one combo
- 9 years agoHelpfull: Yes(0) No(0)
- ans is : c
a = 1 : (1,3,5)//////
a = 3 : (3,5,7)//////
a=41 :(41,43,47)////////// - 9 years agoHelpfull: Yes(0) No(5)
- only 1 soln is possible when we put a=3 then we get only 3,5,7
- 9 years agoHelpfull: Yes(0) No(0)
- three cases are possible
a=1,3,5 - 9 years agoHelpfull: Yes(0) No(2)
- lage raho dosto infinity hoga....
- 9 years agoHelpfull: Yes(0) No(5)
- option a..
bcoz 1 is not prime n 3 is the lone no. satisfying the condition..
so 3. - 9 years agoHelpfull: Yes(0) No(1)
- option:-B bcoz....when put
a=3 3,3+2=5,3+4=7
so , 3,5,7
a=17 17, 17+2=19 ,17+4=23
so, 17,19,23
- 9 years agoHelpfull: Yes(0) No(4)
- Only one solution which is a=3..3,5,7
@akhil dhawan Bandhu 1 is not prime number - 9 years agoHelpfull: Yes(0) No(0)
- Answer is more than 3...
1 is not a prime number nor a composite number,a number which is divisible itself and 1 is a prime number..
hence,
Put a =5,11,17,41.... - 9 years agoHelpfull: Yes(0) No(0)
- option d
a=1 then 1,3,5
a=3 then 3,5,7
......... - 9 years agoHelpfull: Yes(0) No(1)
- a=1,3,11
if a=5
5,7,9 nt prime
- 8 years agoHelpfull: Yes(0) No(0)
- 1,3 satisfy only so ans is 2
- 8 years agoHelpfull: Yes(0) No(0)
- b.2 solution
3 and 11 - 8 years agoHelpfull: Yes(0) No(0)
- The only even prime number is 2. If a = 2, then a+2 = 4, and it is composite. So a = 2 is not a solution. Other than two, we have only odd numbers that can be suited to a. If a is odd, then either ‘a’ or ‘a + 2’ or ‘a + 4’ is definitely a multiple of 3. (3 consecutive numbers/3 consecutive odd numbers/3 consecutive even numbers will have always a multiple of 3, and their sum will always be a multiple of 3).
So, we have the only option left with us as a = 3. If a = 3, then we have a + 2 = 5 and a + 4 = 7, and all these numbers are prime. So, we have only 1 solution. - 7 years agoHelpfull: Yes(0) No(0)
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