Brain Teasers [Puzzle Sms]
Agar Aap Race Mein Doosray Number Pe Aanay Walay Ko Overtake Kar Gaye Toh Aap Kaunsi Position Pe Huay?
Baseball bat and ball cost $50.
If the bat cost $49 more than the ball, what is the cost of each.
Ans: 49.5$ and 0.5$
Four people need to cross a dark river at night.
They have only one torch and the river is too risky to cross without the torch.
At max two people can cross simultaneously.
Speed of each person of crossing the river is different.cross time for each person is 1 min, 2 mins, 7 mins and 10 mins.
What is the shortest time needed for all four of them to cross the river ?
1 and 2 go cross
2 comes back
7 and 10 go across
1 comes back
1 and 2 go across
Total time = 2 + 2 + 10 + 1 + 2 = 17 mins
A 3 digit number is such that it's unit digit is equal to the product of the other two digits which are prime. Also, the difference between it's reverse and itself is 396.
What is the sum of the three digits?
Number : 236
Sum : 11
Outside a room there are three light switches. One of switch is connected to a light bulb inside the room.
Each of the three switches can be either 'ON' or 'OFF'.
You are allowed to set each switch the way you want it and then enter the room(note: you can enter the room only once)
Your task is to then determine which switch controls the bulb ??
turn on 1st switcch for few min. and then turn off.... turn on second switch ..enter the room ..if bulb is on then obviuosly second switch....if not then touch it through hand if the bulb is heated the switch is 1st one, o/w third switch is for bulb
You can place weights on both side of weighing balance and you need to measure all weights between 1 and 1000. For example if you have weights 1 and 3,now you can measure 1,3 and 4 like earlier case, and also you can measure 2,by placing 3 on one side and 1 on the side which contain the substance to be weighed. So question again is how many minimum weights and of what denominations you need to measure all weights from 1kg to 1000kg.
For this answer is 3^0, 3^1, 3^2... That is 1,3,9,27,81,243 and 729