Question

Using a 20 sides number cube, what is the probability that you will roll an even number or a prime number? The number 1 isn't an odd prime number. Round to two decimals.

Answer 1

@moli1993

Answer 2

does side means the number of faces of cube
like in normal dice we have 6 faces ?

Answer 3

Yea

Answer 4

the number of prime numbers in between 1-20 (inclusive)
are
2,3,5,7,,11,13,17,19
and even numbers are
2,4,6,8,10,12,14,16,18,20
right ?
or did i left out something ?

Answer 5

no thats right

Answer 6

so probability of getting even number is 10/20
and probability of getting odd number is 8/20

Answer 7

sorry prime not odd

Answer 8

yupp

Answer 9

umm then u can either have even number or prime number
so total probability is= p(even number)=p(prime number)

Answer 10

which is 8/20+10/20
=0.90 is the answer

Answer 11

Ok, thanks so much

Answer 12

ur welcome :)

Answer 13

could you help with another one?(:

Answer 14

yup sure