Question

One ticket is elected at random from 100 tickets numbered $00,01,02,.....99$. Suppose $X$ and $Y$ are the sum and product of the digit found on the ticket $P(X=7/Y=0)$ is given by

• A. $2/3$
• B. $2/19$
• C. $1/50$
• D. $3/19$

Answer 1

The correct option is B $2/19$

$Y=0$ can be done if one digit is $0$ ,i.e. in the following ways: $00,01,02,...09,10,20,30,40,...90$ i.e. $19$ ways.
Of these, $X=7$ is possible when the number is $07$ or $70$ i.e. $2$ ways.
Probability = $\frac{2}{19}$