Let the fraction be m/n (both m and n are integers, and m and n are coprime).

(m+2)/(n+3)=3/4 ( 1)

1 & lt； (m+3)/(n+ 1)& lt； 2 (2)

N-2

4m = 3n+ 1 (3) is obtained from (1) with1< n <; nine

so 4 < 3n+ 1 & lt； 28， 1 & lt； M< seven

From (3), there is n = (4m-1)/3 = m+(m-1)/3.

Obviously, m- 1 is divisible by 3, while 0

M- 1 can only be 3, so m=4.

n=4+ 1=5

This score is 4/5.