when average age of 25 members are 0 , how many members greater than 0 ?
"average of 25 numbers = 0 . sum of 25 numbers ( 0 x 25 ) = 0 . it is quite possible that 24 of these numbers may be positive and if their sum is a then 25 th number is ( - a ) answer is 24 ( b )"
subtract(25, const_1)