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

### Instruction:
Tom decided to go on a trip. During this trip, he needs to cross a lake, which in one direction takes 4 hours. During this time, Tom needs an assistant to help him with the crossing. Hiring an assistant costs $10 per hour. How much would Tom have to pay for help with crossing the lake back and forth?

### Response:
 Kuvuka ziwa mara mbili (kwenda na kurudi) kutachukua masaa 4 * 2 = <<4*2=8>>8.
Hivyo Tom atalazimika kulipa msaidizi 8 * 10 = $<<8*10=80>>80.