Answer:
The right answer minimum number of $5 cetificates that each nephews and nieces will get is 2 and maximum number of $5 certificates that each will get is 4.
Explanation:
The minimum number of $5 certificates that each nephews and nieces will get is 2 because he can add $25 + $10 = $35 , he has now capacity of $20 ($55 - $35) in which he can add one more $10 the he must have to add 2 of $5 certificates.
The Maximum number of $5 certificates he can give is 4 because again when he adds every certificate once he has capacity of $20 ( $55 - $25 - $10). He can now add 4 * $5 = $20 so he can get $55.
