1. There were 2 systems A n B.14 degrees in A is equivalent to 36 in System B and 133 in A is equivalent to 87 in B. now what is the Temperature where they both r equal?

Answer : 52.5

Approach :

take x+14y=36...(1)

and x+133y=87...(2) and solve (1) and (2) u get x and y values. then put x and y values in equ..(1)and instead of 14 and 36 u put 'A'. so u get it the value as 52.5

2. A slow coach starting from Amristar at 0900hrs reaches Delhi by 0930hrs after 3 days. If a slow coach starts from Delhi to Amristar, how many trains will it meet on its way to Amristar?

Answer : 7 trains

3. No divisible by 3,4,5,7 & is less than 500 (3marks)

Answer : 420

4. In the construction of a house these were required

Designer and Painter equals Rs. 1100-----à1

Painter and Plumber equals Rs. 1700----à2

Plumber and Electrician equals Rs. 1100----à3

Electrician and Constructor equals Rs. 3300-----à4

Constructor and Mechanic equals Rs. 5300----à5

Mechanic and Painter equals Rs. 3200-----à6

What are their individual costs? ( 3 marks )

Answer :

Designer=200; Painter=900; Plumber=800; Electrician=300; Constructor=3000; Mechanic=2300. ( 100% sure )

Take 3 => pl + el = 1100

ð pl+ (3300-co) = 1100 ( from 4 )

ð pl + 3300-(5300-mec) = 1100 ( from 5)

ð pl + 3300-5300+mec=1100

ð Pl+3300-5300+(3200-pa)=1100 ( from 6)

ð Pa-pl = 100---à7

ð And pa+ pl= 1700---à2

ð By solving 7 and 2 we get pa = 900 and pl = 800.

5. In a woods, there were certain birds in each tree. Number of birds in each tree equals to the number of trees in the woods. There are around 2000 - 2100 birds altogether in the woods.What is the total number of trees in the woods?

Answer :

If number of trees in woods is x .Then number of birds is x^2…so look for perfect square b/w 2000 n 2100 .2025 is a perfect square ie 45*45 =2025…so x ,number of trees in woods=45.

6. Five thief's are decided to stole the diamond from a jewellery shop. First person went into the shop and he stolen half of the diamonds plus 2 and the second person went into the shop and he stolen half of the remaining plus 2 and the third person stolen half of the remaining plus 2 and the fourth person stolen half of the remaining plus 2 when the fifth person entered into the shop only one diamaond is left. How namy diamonds are there in the shop?

Answer :

let us think there r x diamonds in the shop.
First person went and taken half of the diamonds plus 2 i.e x/2 +2
Then the remaining diamonds are x-[x/2+2] = (x-4)/2
second person went into the shop and taken half plus 2
=(x-4)/4 + 2
then the remaining diamonds are (x-4)/2 - ((x-4)/4 + 2) and this will be continued
and the answer is 76

7. Two friends are playing a game. They had abet of $1 for every match. A won 3$ and where as B won 3 matches. How many matches are totally played.

Answer :

(This question if from shakuntala devi (more puzzles) book)
B won 3 matches means he won 3$
Then A won 3 matches means he won 3$
Here both have won 3$ which is equal.
And at last A won 3 mathes which he won 3$
So totally 9 games are played

8. Mary had some amount of money in her purse and she went out. She first spent half of her money in shopping and then donated a rupee to a beggar. Then from the remaining money she spent half of her money in dining and gave rs.to the waiter. From the remaining money she invested half the money and brought flowers and finally she had 1 Rs left. [The question is something like this. I am not sure about the figures]. You are supposed to find the actual amount of money Mary had with her in the end.

Answer : 42

9. A 10 digit number has it first digit equals to the numbers of 1's,second digit equals to the numbers of 2's ....till 9th digit equals to the numbers of 9's and 10th digit equals to the number of 0's.what is the number? (6 marks)

Answer : 2100010006 (Trial and error)

10. A passenger train requires twice the time to overtake the freight train as it takes to cross the freight train when it is coming in opposite direction. How much faster is the passenger train in comparison with freight train? ( 3 marks) . ans) thrice.

Answer :

let time taken by passenger train to cross freight (opposite direction) = t sec.=d/(sp+sf)

Then Time taken by passenger to overtake freight (same direction) = 2t sec. =d/ (sp-sf)

where total distance = d meters.

Speed of passenger = sp

Speed of freight train = sf

So d / ( sp-sf) = 2d/(sp+sf)

ð sp = 3sf.

ð So passenger train is 3 times faster than freight train.