###Human: Olivia gave William 10 napkins. Amelia also gives William twice the number of napkins Olivia gave him. If William had 15 napkins before, how many napkins does he have now?, ### Assistant: After Olivia gave William 10 napkins, he ends up with 15+10= 25 napkins.
Amelia gives William twice the number of napkins given to him by Amelia which is 2*10 = 20 napkins.
The total number of napkins William has now is 20+25 = 45 napkins. 
 So the answer is :  45