A person starts multiplying consecutive positive integers starting from 20. How many numbers should he multiply before he will have a result that will end with 3 zeroes?

No worries! We‘ve got your back. Try BYJU‘S free classes today!

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

No worries! We‘ve got your back. Try BYJU‘S free classes today!

Open in App

Solution

The correct option is C
6

A number will end in 3 zeroes when it is multiplied by three 10s.
To get a 10, one needs a 5 and a 2.
$20 = 2 \times 10 ⟹ 20$ will give one zero and it has one extra 2.
So, to get three zeroes he should multiply till he encounters two more 5s and one more 2.
Since 25 has two 5s and 22 has one 2 $⟹$ he should multiply till 25 i.e. 20, 21, 22, 23, 24, 25 = 6 numbers.

Suggest Corrections

Similar questions

Q. Multiplying prime numbers

> 1

< 100

consecutively, how many zeroes will result at the end?

Q. If we multiply first 50 prime numbers. How many zeros at the end will such a product have?

Q. If we multiply first 50 prime numbers, then how many zeros will such a product have at the end?

Let $S$ be the set of prime numbers greater than or equal to $2$ and less than $100$ . Multiply all elements of $S$ . With how many consecutive zeros will the product end?

If a number ends with 3 zeroes, how many zeroes will its square have ?

Join BYJU'S Learning Program