90kg
It is just a simple proportional problem. If you subtract 10%, then you subtrat 10 kg.
Answer:
C
Step-by-step explanation:
0.28x=13.44
Answer:
1.46
Step-by-step explanation:
First find the the mean score before he made a 90.

Now add the score of 90 and calculate.

Subtract the two scores.

His mean test score increased by 1.46.