I have tried Dogars, Bank Officer guide and I think its enough...Rest depends on your comprehension ability.

@Exculsive fairy...You got my quote as your signature " Intellectual growth should commence at birth and ceased only at death" By Einstein...

If ther are 7 teams in a tournment, in 1st round each team play atleast one match with other teams. Find the total number of matches played in 1st round?

How many 4 digit number can be made using 1, 2, 4 and 6?

Explain with logic?

1. 21
2. 256 ( n^r)

correct me if wrong

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7*6=42 then 42/2=21

4!=24

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Explain True or false?

-27 minutes before 7 o'clock is 33 minutes past 5 o'clock.

-If written backwards, the number, "one thousand, one hundred twenty-five," would be written "five thousand, two hundred eleven."

-A round wall clock that has been rotated until it is hanging upside down will have a minute hand that points to your right when it is two forty-five.

-If Richard looks into a mirror and touches his left ear with his right hand, Richard's image seems to touch its right ear with its left hand.

-Sixteen hours are to one day as twenty days are to June's length

-If a thumb is a finger, then three gloves and three shoes normally hold thirty-five fingers and toes

-Without breaking or bending a toothpick, you can spell the word, "FIN," with exactly seven toothpicks, with no letter sharing a toothpick used by another letter.

How we can expand 4!=1*2*3*4=24?

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Aalam-e-soz o saz main, wasl se barh ker hai firaaq
Hijr me lazt-e-talb, wasl main marg-e-arzoo...!!!

At the end of a banquet 10 people shake hands with each other. How many handshakes will there be in total??????

A. 100
B. 20
C. 45
D. 50
E. 90

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Success does not consist in never making blunders, but in never making the same one a second time.

45

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1st one is right
2nd one also if the number can be used repeatedly
thxs for this formula

This answer is right if the number only can be used once. But my ? it is either n! or r!.
It means that if question is How many 4 digit number can be made using 1,2,3 and 4 without repeating any number?

The answer would be same i.e n!=4! = 1*2*3*4=24

Correct me if i am wrong

Plz elaborate your answer

plz explain how?

__________________
Success does not consist in never making blunders, but in never making the same one a second time.

Well when 10 people have shaken hands, it means every one person has shaken hand with 9 other people...so it should be 90.