Question

If a shopkeeper earns Rs.400 a day when it is a weekend and Rs.300 a day when it is a working day. What should be his bearning expectation if the probability of it being a weekend today is 0.6 ? A) 240 B) 120 C) 360 D) 700​

Answer 1

Given:

• Earnings of the shopkeeper on a weekend day = $Rs.400$
• Earnings of the shopkeeper on a weekday = $Rs. 300$
• The probability of today being a weekend = $0.6$

To find:

Today's earning expectation of the shopkeeper, if the probability of today being a weekend is $0.6$.

Formula to be used:

• Let the earning on weekend day be denoted by "$W$".
• Let the probability be denoted by "$P$".
• Let the earning expectation be denoted by "$E$".
• Now, the required earning expectation of the shopkeeper for weekend day with given probability is calculated as follows:

$E=W*P$......(1)

Solution:

• From the given data, the probability of today being working day is $0.6$.
• Earning of the shopkeeper on a weekend day is $Rs.400$.
• Using the equation (1), the earning expectation of the shopkeeper is calculated in the following manner:

$E=W*P\\E=400*0.6\\E=240$

⇒The required earning expectation of the shopkeeper when there is $0.6$ probability for today being a weekend is $Rs.240$

Final Answer:

The earning expectation of the shopkeeper if the probability of today being a weekend is $0.6$ is $Rs.240$.