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Bunuel
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Is it just me or did I find this question ambiguous? I thought it was asking what's the probability that the last digit is 1,3,7,9

P(1,3,7,9) = 2/5

The responses above assume that this is a four-digit integer we are looking for (unclear in the stem) and the fact that each integer is 1,3,7,9. In which case I would agree that the probability is

2/5 x 2/5 x 2/5 x 2/5 = 16 / 625

Bunuel?
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CEdward

Need to note here..

There are total of 4 positive integers (not necessarily 4-digit positive integers)..

further, For each of the 4 positive integers , the probabilty of finding 1, 3. 7 or 9 as its last digit is 2/5. (ie, selcetion of 1/3/7/9 from 0/1/2/3/4/5/6/7/8//9)

Accordingly, the overall probabilty of selecting such 4 postive integers, with the overall prodct having one amogst 1/3/7/9 will be :-

2/5 * 2/5 * 2/5 * 2/5 = 16/625

Hope it helps..!!
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The question refers to positive digits. Should not we exclude 0 from answer calculation? Bunuel
Bunuel
What is the probability that the units digit of the product of four positive integers is 1, 3, 7, or 9 ?

A. 16/625
B. 81/625
C. 2/5
D. 3/5
E. 609/625


Are You Up For the Challenge: 700 Level Questions

If 4 whole numbers taken at random are multiplied together, what is the probability that the last digit in the product is 1,3,7 or 9?
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George1610177
The question refers to positive digits. Should not we exclude 0 from answer calculation? Bunuel
Bunuel
What is the probability that the units digit of the product of four positive integers is 1, 3, 7, or 9 ?

A. 16/625
B. 81/625
C. 2/5
D. 3/5
E. 609/625


Are You Up For the Challenge: 700 Level Questions

If 4 whole numbers taken at random are multiplied together, what is the probability that the last digit in the product is 1,3,7 or 9?
The 4 positive integers could include a 10, 20, 100, etc. and units digit will turn out to be 0 in that case.
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