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

### Instruction:
Brody’s calculator can run for 60 hours on a full battery. Brody has used three quarters of its battery up, and he is about to take a two-hour math exam that will require his calculator the whole time. How many hours of battery will Brody’s calculator have left?

### Response:
 Kikokotoo cha Brody kina masaa 60 * 1/4 = 60 / 4 = <<60*1/4=15>>15 ya betri iliyobaki.
Baada ya mtihani wake wa hesabu wa masaa 2, kikokotoo cha Brody kitakuwa na masaa 15 - 2 = 13 ya betri iliyobaki.