If any four numbers are selected,what is the | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(C) The last digit of a product depends only on the last digits of the individual numbers.For any single number,the possible last digits are $\{0, 1,

Vedclass · Accepted Answer

$\frac{16}{625}$

Vedclass · Answer

(C) The last digit of a product depends only on the last digits of the individual numbers.For any single number,the possible last digits are $\{0, 1, 2, 3, 4, 5, 6, 7, 8, 9\}$,so there are $10$ possibilities.For the product of four numbers to have a last digit of $1, 3, 5$ or $7$,each of the four numbers must have a last digit from the set $\{1, 3, 5, 7\}$.The probability that a single number has a last digit in $\{1, 3, 5, 7\}$ is $P = \frac{4}{10} = \frac{2}{5}$.Since the four numbers are selected independently,the probability that all four have a last digit in $\{1, 3, 5, 7\}$ is $\left(\frac{2}{5}\right)^4 = \frac{16}{625}$.

If any four numbers are selected,what is the probability that the last digit of their product will be $1, 3, 5$ or $7$?

Similar Questions

$A$ die is rolled. Let $E$ be the event "die shows $4$" and $F$ be the event "die shows an even number". Are $E$ and $F$ mutually exclusive?

$A$ man alternately tosses a coin and throws a dice,beginning with the coin. The probability that he gets a head in the coin before he gets a $5$ or $6$ in the dice is

When two dice are thrown,what is the probability of getting a sum of $7$ (in $/36$)?

$A$ bag contains $5$ black balls, $4$ white balls and $3$ red balls. If a ball is selected at random, the probability that it is a black or a red ball, is

Vedclass Test Series

Exam Paper Generator

Online Exam Module