In a class, six students named P, Q, R, S, T and U obtain different marks out of total 100 marks. The ratio between marks of T and S is 2: 3 respectively. P obtains 50% marks. R obtains 5 marks less than P. U obtains 1.5 times of the marks obtained by P. T obtains less marks U but more marks than R. Q obtains 20 marks more than T. The ratio between marks of T and U is 4: 5 respectively. Which of the following is true based on the given information?
I.   S obtains 90% marks which are the highest among all.
II.   The ratio between marks of P and Q is 5: 8 respectively.