Question

All even numbers from 2 to 98 inclusive, except those ending 0, are multiplied together. what is the rightmost digit (the units digit) of the product?

Answer 1

ans is 6
first multifly all numbers ending with 2 those are 2*12*22*32*42.......*92=2^10=4 is last digit
multify all numbers ending with 4=4^10=6 last digit
multify all numbers ending with 6=6^10= 6 last digit
multifly all numbers ending with 8=8^10=4 last digit
so 4*6*6*4=6 last digit

Answer 2

$\huge \mathbb{your \: answer \: mate=>}$

❇our multipliers are:

2,4,6,8,12,14,16,18,22,24,....94,96,98

multiplying them starting with 2x4 we get answers that end in

8,8,4,8,2,2,6,2, and then the same sequence repeats.

You will also notice that after each multiplier that ends in 8, like 18 or our last one 98, the answer ends in either 6 or 4.

So all we have to do is decide if it's a 4 or 6

$\huge \underline \mathfrak{reason:-}$

There are 48 even numbers up to the 98, but we have to exclude mulipliers ending in 0 such as 10,20,..

there are 10 of these, so we are down to 40 multipliers resulting in 39 answers

Our loop of last numbers has a length of 8

39÷8 = 4.875 wich is near the end of the loop of reapeating digits,

so it must be the 6

$\huge \mathfrak{hope \: it \: helps}$