Jake ate 3 pieces of candy. His sister ate 4 tines as much as him. His many pieces of candy dus His sister eat
His sister ate 3 * 4 = <<3*4=12>>12 pieces of candy. Answer: \boxed{12}.
To find out how many pieces of candy Jake's sister ate, we need to multiply the number Jake ate by 4.
Jake ate 3 pieces of candy.
So, Jake's sister ate 4 times as much, which is 3 x 4 = 12 pieces of candy.
Therefore, Jake's sister ate 12 pieces of candy.