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

### Instruction:
 Tatuya, Ivanna, na Dorothy walifanya mtihani pamoja. Tatuya alipata alama mara mbili ya Ivanna, na Ivanna alipata 3/5 ya alama za Dorothy. Ikiwa Dorothy alipata alama 90, hesabu wastani wa alama walizopata watatu hao.


### Response:
 Kwa kuwa Dorothy alipata alama 90, na Ivanna alipata 3/5 ya alama hizo, Ivanna alipata 3/5*90 = <<90*3/5=54>>54 alama.
Pamoja, Dorothy na Ivanna walipata jumla ya alama 54+90 = <<54+90=144>>144.
Tatuya alipata alama mara mbili ya Ivanna, hivyo alipata 2*54 = <<2*54=108>>108 alama.
Jumla ya alama walizopata watatu hao ni 108+144 = <<108+144=252>>252.
Hesabu wastani wa alama kwa watatu hao ni 252/3 = <<252/3=84>>84 alama.