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

### Instruction:
Tara is saving up to buy a new clarinet. She already has $10 saved. The clarinet costs $90. She plans to sell her old books to make the money. She sells each book of hers for $5. However, when she is halfway towards her goal, she loses all her savings and has to start over. How many books does she sell in total by the time she reaches her goal?

### Response:
 Nusu ya lengo lake ni $45 kwa sababu 90 / 2 = <<90/2=45>>45
Anauza vitabu vyenye thamani ya $35 kabla ya kupoteza pesa kwa sababu 45 - 10 = <<45-10=35>>35
Anauza vitabu 7 kabla ya kupoteza pesa kwa sababu 35 / 5 = <<35/5=7>>7
Kisha anauza vitabu 18 kwa sababu 90 / 5 = <<90/5=18>>18
Anauza vitabu 25 jumla kwa sababu 18 + 7 = <<18+7=25>>25