Below is an instruction that describes a task. Write a response that appropriately completes the request in Swahili. Please answer in Swahili.

### Instruction:
A 40-bead necklace is made up of three kinds of beads. There are seven amethyst beads and twice as many amber beads as amethysts. The third beads are turquoise. How many turquoise beads are in the necklace?

### Response:
 Kuna vito vya dhahabu 7 * 2 = <<7*2=14>>14.
Hivyo, kuna jumla ya vito vya ametisti na dhahabu 14 + 7 = <<14+7=21>>21 katika shanga hiyo.
Hivyo, kuna vito vya rangi ya kijani ya bahari 40 - 21 = <<40-21=19>>19 katika shanga hiyo.