A stack of five cards has the numbers 1,3,5,7,9 on them. They are placed face down and one card is pulled out, the number noted and placed back again. Which one of the following is a possible total sum, after six such draws? Give reason for your answer. Options are - 4, 19, 27, 28, 60.
I am explaining this via shortcut ie hit and trial method.
add all the 5 numbers. 1+3+5+7+9 , we get 25.
Adding 3 will give 28 .
So the card number opened will be 1,3,3,5,7,9 .
They can be in any order.
2nd way :
All are positive number ,so -4 can't be answer.
All are odd number so there sum will be only even so 19 and 27 cant be the answer .
If all number picked is 9 , then sum would be 9+9+9+9+9+9=54 .This will be the maximum value .So 60 cant be answer .
So only possible answer is 28 .
Hope this would have cleared your doubt .