How to determine if an Egg is fresh

1.  Place the egg in a bowl of water.

2.  If the egg lays on its side at the bottom, it is still quite fresh.
3.  If the egg stands upright on the bottom, it is still fine to eat, but should be eaten very soon, or hard-boiled.
4.  If the egg floats to the top, it's past its prime, and not good for eating.

Why this method is accurate?

Eggshells are very porous. Over time air passes through the shell into the egg, and its shelf life diminishes as more air enters the shell. Also, the more air that enters the shell, the more buoyant the egg becomes.

Multiply Up to 20X20 In Your Head

In just FIVE minutes you should learn to quickly multiply up to 20x20 in your head.  With this trick, you will be able to multiply any two numbers from 11 to 19 in your head quickly, without the use of a calculator.

I will assume that you know your multiplication table reasonably well up to 10x10.

Try this:

• Take 15 x 13 for an example.
• Always place the larger number of the two on top in your mind.
• Then draw the shape of Africa mentally so it covers the 15 and the 3 from the 13 below. Those covered numbers are all you need.
• First add 15 + 3 = 18
• Add a zero behind it (multiply by 10) to get 180.
• Multiply the covered lower 3 x the single digit above it the "5" (3x5= 15)
• Add 180 + 15 = 195.

Product of Numbers close to 100:

Lets take you have to multiply 91 and 95 . First take their difference from 100. ie 100-91=9and 100-95=5 . Now reduce this difference from the other number .ie 91-5 or 95-9 ==86 . This is the first 2 digits of the result . Now for the last 2 digits just multiply the differences ,ie, 9*5=45.

So the result is  91*95=8645.

How many squares are there?

How many squares are there?

Usually, we get some puzzle like this. I would like to share trick that can solve this kind of puzzle so easily.
In perfect 4*4 square, to find out the number of squares,
4^2=16
3^2=9
2^2=4
1^1=1
Total number of squares would be 16+9+4+1=30.

Same ways, the answer for squares in 7*7 is,
49+36+25+16+9+4+1=140.

This works perfectly fine when there are same number of rows and columns.

But what if, there are different numbers of rows and columns into it.
For Example,

if there is a rectangle, which has 5 rows and 4 columns and still we have to find the total number of square in it. It would not be possible with the above method.

For this, there is a simple trick,

Rows- 5 Column-4

STEP 1) Multiply the number of rows into number of column
In this case 5*4 = 20
STEP 2) Reduce 1 from number of rows and column
In this case 4*3 = 12
STEP 3) Follow STEP 2 until either of row or column count comes to 1.
In this case 3*2 = 6, 2*1 =2

As we see above the column count has come to 1 so reducing it to zero wont make any sense. 

Total = 20 + 12 + 6 + 2 = 40

Square a 2 Digit Number Ending in 5

For this example we will use 25

• Take the "tens" part of the number (the 2 and add 1)=3
• Multiply the original "tens" part of the number by the new number (2x3)
• Take the result (2x3=6) and put 25 behind it. Result the answer 625.

Try a few more 75 squared ... = 7x8=56 ... put 25 behind it is 5625.
55 squared = 5x6=30 ... put 25 behind it ... is 3025. Another easy one! Practice it on paper first!

Common Mistakes in English

1. Usage of "marriage anniversary" in place of "wedding anniversary"
2. Usage of "doubt" in place of "question"
3. Usage of "have/had had"
4. Confusion between usage of "there", "their" and "they're"
5. Confusion between usage of "loose" and "lose"
6. Usage of "cope up with" instead of "cope with"
7. Usage of "my/your/our-self/selves" after resist.
8. Usage of "take out" instead of "find/calculate"
9. Usage of "How is [x] like?" instead of "What is [x] like?"
10. Usage of "Many a times" instead of "many times/many a time/a lot of times"
11. Usage of 'You need not to [do x]' instead of 'you need not [do x]' or 'you do not need to [do x]'
12. Usage of "return back", "revert back", "reply back", etc. instead of "return" "revert", "reply", etc.
13. Usage of "competition" after debate or quiz.
14. Usage of plurals after "doesn't" such as 'doesn't fits', 'doesn't matters' instead of 'doesn't fit', 'doesn't matter'
15. Addition of "about" like in 'Discussing about [x]' instead of 'discussing [x]'
16. "Commonsensical" instead of "matter of common sense". Commonsensical is not a word.
17. "Be rest assured" instead of "rest assured" or "be assured".
18. Usage of additional "as" after "called" like in "This website is called as Quora"
19. Usage of "but" along with "although"
20. Usage of "if yes/not" instead of "if your answer is yes/no"
21. Usage of "know more" instead of "find out more"
22. Usage of standalone "basis" instead of "on the basis of" in a sentence.
23. Usage of "equally as [adjective] as" instead of "as [adjective] as"
24. Usage of "did" instead of "made" as in "I did a mistake"
25. Usage of "me" right after "suggest/recommend"
26. Usage of "off" instead of "of"
27. Usage of a negative condition with "until/till"
28. Using 'Myself [so-and-so]' in place of 'I'm [so-and-so]'.
29. Usage of "I don't think so that.." instead of "I don't think that.."
30. Usage of [verb in the past tense] after "didn't"
31. Usage of 'More [comparative adjective that ends in -er]' instead of only [comparative adjective that ends in -er]
32. Usage of plural form instead of singular form like alumni instead of alumnus.
33. Usage of "was" with "if/wish"
34. Usage of "Who" with a relative pronoun
35. Usage of between instead of among.
36. When using or, either, neither, nor the succeeding verb would follow the form nearest to it.
37. Usage of two comparative terms together.
38. Usage of suffixes with Roman numerals.
39. Usage of "pass out/away" instead of "graduate". [Not always - Google]
40. Usage of "see/look at/watch"
41. Usage of goggles/shades/glasses-spectacles. (Correct: "... a pair of goggles...")
42. Usage of "on the" instead of "on a".
43. Usage of 'only' to emphasize actions.
44. More better instead of "better" or even "better".

45. Usage of has/have; for example 'I has/You has' instead of I have/ You have'

Source :https://www.quora.com/Grammar/What-are-the-most-common-English-language-and-grammatical-errors-made-by-people-from-India