The score is indeed 89. 1.

In this kind of topic, "Chinese achievement" after "Bi" should be regarded as the unit "1"

Math scores are more than the unit "1" 1/9.

Math scores are 10/9 of Chinese scores.

It is known that the comparison quantity (that is, mathematical fraction) needs the quantity of unit "1", which is divided by division.

Then 99/(1+1/9) = 89.1(minutes)

Hope to adopt