Since Dorothy scored 90 marks, and Ivanna scored 3/5 times as many marks, Ivanna scored 3/5*90 = <<90*3/5=54>>54 marks.

Together, Dorothy and Ivanna scored a total of 54+90 = <<54+90=144>>144 marks.

If Tayuta scored twice as many marks as Ivanna, she scored 2*54 = <<2*54=108>>108 marks.

The total marks the three scored altogether is 108+144 = <<108+144=252>>252 marks.

The average marks for the three are 252/3 = <<252/3=84>>84 marks.

# Answer

84
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
Tatuya, Ivanna, and Dorothy took a quiz together. Tatuya scored twice as much as Ivanna, and Ivanna scored 3/5 times as many marks as Dorothy. If Dorothy scored 90 marks, calculate the average marks scored by the three.
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
84
Tatuya, Ivanna, and Dorothy took a quiz together. Tatuya scored twice as much as Ivanna, and Ivanna scored 3/5 times as many marks as Dorothy. If Dorothy scored 90 marks, calculate the average marks scored by the three.
train