Question

Find the last digit in the product of any 15 consecutive 2digit odd natural numbers

Answer 1

As a result, the last digit in just about any 15 consecutive 2 digit odd positive integers equals 5.

What about Consecutive numbers?

• Consecutive numbers are numbers that follow each other in a sequence in mathematics. The definition of consecutive numbers is "numbers that follow each other in sequence from least to greatest."

Solution :

• Product of 15 consecutive 2 digit odd natural number

        = 51×53×55×57×59×61×63×65×67×69×71×73×75×77×79

• Last number in any 15 consecutive 2 digits odd natural numbers' product

Unit digit in the product ( $1X3X5X7X9X1X3X5X7X9X1X3X5X7X9$)

⇒ 843,908,625

As a result, the last digit in just about any 15 consecutive 2 digit odd positive integers equals 5.

Answer 2

Answer:

The last digit in the product of any 15 consecutive 2digit odd natural numbers is 5.

Explanation:

As per the data given in the question,

We have to find product of any 15 consecutive 2digit odd natural numbers

Lets assume number starting from 11

So, products of 2 digit odd numbers starting from 11 are:

$=11\times13\times15\times17\times19\times21\times23\times25\times27\times29\times31\times33\times35\times37\times39$

So, the product of last digit will be:

$=(1\times3\times5\times7\times9)^{3}$ as it is repeating

$=(945)^{3}$

So, the last digit will be 5.

Hence,

The last digit in the product of any 15 consecutive 2digit odd natural numbers is 5.

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