Questions

The EKG was invented by Willem Einthoven in 1903 and is used to monitor and analyze past and present heart activity in an individual.

During convection, cool and dense air falls through the warmer and less dense air. The warm air having less mass is being displaced by the cooler which is much heavy. Convection always involves the air rising through the atmosphere.

The given math puzzle follows a logic that,

1 + 4 = 5 => 1 x 4 + 1 = 5

2 + 5 = 12 => 2 x 5 + 2 = 12

3 + 6 = 21 => 3 x 6 + 3 = 21

Similarly,

8 + 11 = > 8 x 11 + 8 = 96.

The paste applied to the side of a match box is a mixture of phosphorus trisulphide, glass powder (or sand) to cause friction and glue (binding material)

Baltic Sea White is thelongest Canal.It is in Russia

At least one black can be chosen in two ways from each box:
Now, probability of choosing at least one black ball from first box 

= 1/2 × [ (2C1× 2C1)/4C2 + 2C2/ 4C2 ]= 5/12

Probability of choosing at least one black ball from 2nd box
= 1/2 × [(4C1×12C1)/16C2 + 4C2/ 16C2] = 9/40

Final probability

= 5/12 + 9/40 = (50 + 27)/120 = 77/120

In 1773, several colonies of North America refused to unload the tea coming in English ship.In Boston, when the governor ordered a ship to be unloaded, a group of citizens, dressed as American Indians, boarded the ship and dumped the crates of tea into the water. This incident is known as the 'Boston Tea Party '.