Answer:
The probability is 0.9
Step-by-step explanation:
Suppose that we have a bag with N outcomes (such that these N outcomes have the same probability of being randomly drawn from the bag, we can suppose that the outcomes are given elements, like marbles or something like that.)
Suppose now that there are K of these elements with a given property.
The probability of randomly drawn one of these K elements is equal to the quotient between the number of these elements in the set (K) and the total number of elements in the bag (N)
The probability is: P = K/N
In this case, we know that there are 40 slips of paper, numbered from 1 to 40.
We want to find the probability of NOT choosing a multiple of 10.
The multiples of 10 in that range are:
10*1 = 10
10*2 = 20
10*3 = 30
10*4 = 40
So we have 4 multiples of 10, then we have 36 non-multiples of 10.
The probability of drawing at random a number that is not a multiple of 10, is equal to the quotient between the number of slips of papers with numbers that are not multiples of 10 (36) and the total number of slips of paper (40)
P = 36/40 = 0.9
The probability is 0.9