<prompt> Translate the following text to EnglishWakati baadhi ya mtaji wao ni kuwekeza katika dhamana Treasury, riba ni kuhusiana na gharama zao za shughuli kwa njia sawa na mapato yanayopatikana kutoka kuuza huduma.  <response>: When some of their capital is invested in Treasury securities, the interest is related to their cost of operations in the same way as the revenue earned from selling services. 