Faculty : Vishal Sharma More than 16 years of experience in CAT training Trained 10000+ students till date

Concept of Trailing number of Zero Important Concept of Number System CAT/MBA Entrance

Factorial: Let's Understand it Question is how many trailing zero's are there in 100!? .22.1 3 3.2.1 6 ANY GUESS! SO ON.

Trick is we will look for Co-prime factors of 10 10=5*2 Let's learn the concept Key is to identify how do we get trailing zero.. 2 *10 20 42 * 10 = 420 Focus on 5 Why? So the idea is Multiplication by 10 But then what about 5!- 120 Why do we get zero there?

Let's try the concept . Divide 100 by 5 Quotient 20 . Divide Quotient by 5 New Quotient 4 . We will stop where new quotient on division will be 0 So the number of zero's are 24

Let' s take more questions 1000!

13 lessons,

2h 39m

Enroll

23

✕Download

Vishal Sharma

I am an engineer by education and teacher by choice.I have been training students for CAT exams for 16 years.I have worked with top brands l

Unacademy user

Soumi Rasack

5 months ago

Thanks

1

Reply

Sudheesh Raghavan

5 months ago

👍😊