OH NOOOO !!!!!!!

How many 4 digit numbers are there that don't have a five in them. [with in the range of 1000-9999 Also what is short test method.

#NumberTheory #Numbers #Science #MATHS #Funny

Easy Math Editor

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Comments

The thousands digit can only be 1,2,3,4,6,7,8,9 = 8 digits. Hundreds digits: 9 Tens digits: 9 Ones digit: 9 8 x 9 x 9 x 9 = 5832. I think...

Tan Wee Kean - 6 years, 9 months ago

the question can be stated in another way like this.."how many numbers are divisible by five within 1000-9999" if so, then just use arithmetic progression to get how many numbers are divisible by five..thus, 9995=1005+(n-1)(5), n=1799, then answer is.. 9000-1799=7201

roland casuga - 6 years, 9 months ago

What about 5554? It's not divisible by 5, yet still contain 5 in it.

Samuraiwarm Tsunayoshi - 6 years, 9 months ago

Math	Appears as
Remember to wrap math in `\(` ... `\)` or `\[` ... `\]` to ensure proper formatting.
`2 \times 3`	$2 \times 3$
`2^{34}`	$2^{34}$
`a_{i-1}`	$a_{i-1}$
`\frac{2}{3}`	$\frac{2}{3}$
`\sqrt{2}`	$\sqrt{2}$
`\sum_{i=1}^3`	$\sum_{i=1}^3$
`\sin \theta`	$\sin \theta$
`\boxed{123}`	$\boxed{123}$