Score Plus

Which means the square root of any positive number can be -ve and +ve. If thats the case then I have a few more difficulties.
1) Column A : (sq rt 3)+(sq rt 4)
Column B : (sq rt 7)
Considering only the +ve answers the answer is A but you just mentioned that it can be +ve or -ve so shouldnt the answer be D?

2) Column A : (0.638)^2
Column B : ( sq rt 0.638)
Answer given is B but shouldnt it be D again considering the -ve and +ve solutions?

3) p^2 = 49 and q^2 = 81
Column A : p
Column B: q
Answer given is D. In this case they have considered the -ve solutions thus the answer is D.
How does one know when to consider only the +ve solution and when to consider both ?

4) Column A : 8
Column B : (sq rt 30) + (sq rt 24) .
Answer is B. Again have they ignored the -ve solutions ?

4) 100 ^ 10 /2^ m.what is the greatest integer for m ?
Is the solution 100/1st power of = 50 + 100/2nd power of 2 = 25. Answer is 75. But logically the answer should be 10. Please clarify.

5) In one of the previous posts there was a question mentioning 23 have taken french, 16 have taken german and 7 have taken both, so how many have taken either. The answer supplied was (23-7) + (16-7) = 25.
In the ETS book a similar problem was given and the answer was 23+16-7 = 32. Please clarify.

6) S is the sum of integers 1 to 48 inclusive, V is the sum of all even integers in S, D is the sum of all odd integers in S.
Column A : V
Column B : D +23

7) Column A : Sum of all numbers from 1 to 50 inclusive
Column B : 2525

8) Column A : 31 ^ 11
Column B : 17 ^14

9) Column A: Maximum no of weights which enables to weigh any integer number of grams of gold from 1 to 100 on a std balance with two pans, if weights are placed only on the left pan.
Column B : Column A: Maximum no of weights which enables to weigh any integer number of grams of gold from 1 to 100 on a std balance with two pans, if weights can be placed on either of the pans of the balance.
Answer is A! How ?

10) Two circles with centres O and P intersect at two points. The radius of the circle O is 4 and P is 3.

Column A : The distance from point O t o midpoint of OP
Column B: 3.5
Answer is B, but cant the distance be exactly 3.5? If the circles intersect in such a way that the common line between them is 1 cm long then O to midpoint of OP would be 3.5

hey kunal,
solution 1 - 3:
If we observe keenly, there is a method to the madness.
whenever the question contains the sqrt function...then we are supposed to consider positive roots wonly!

But, if we have a square function in the question and we are forced to take a square root like in question 3...then the uncertainity factor comes in to the picture and then we have to consider both positive as well as negative roots.....hope this helps

6)
in the series of 1 to 48, the even terms are repented by 2,4,6,8,....
Its an AP.....first term: a=2, nth term: Tn = 48,common difference = 2
48 = 2 + (n-1) *2 hence n= 24
sum, Sn =[ n (1st term + last term)]/2
Sn = 24(2 + 48)/2
= 24 * 25
= 600

odd terms: a=1, Tn = 47, common diff = 2
47 = 1 + (n - 1) * 2 hence n =24
sum, Sn = [ n (1st term + last term)]/2
Sn = 24 * (1 + 47)/2
= 576

D + 23 = 599

Thanks, the square root thing did help.
And what about 8,9 and 10 ?

8) Its pretty simple actually...the answer should be 31 ^ 11....i cant give an explanation its quiet evident that 31 ^ 11 is way greater than 17 ^ 14

9) .....no answer yet, will post a reply as soon as i can figure out something

10) the circles intersect in 2 points....

if they were tangents to each other...i.e, the met at only one point then the length OP would have been 7
but here they intersect in 2 points hence OP would be less than 7 umits long

hence the distance between one end of the segment and the midpoint of the segment would be less than 3.5

Thanks for great information