Solution: (1) If Party A and Party B buy clothes together, it will cost 40 × 92=3680 yuan.

Compared with buying clothes alone, it can save: 5000-3680 = 1320 (yuan).

(2) There are X students in a school (according to the meaning of question 46)

50x+60x (92? -x)=5000 8 x=52，

X=52 meets the problem of ∴ 92-X = 40.

A: There are 52 students in A school and 40 students in B school.

(3) Scheme 1: Spend 43× 60+40× 60 = 4,980 yuan on clothes respectively.

Scheme 2: The joint clothing purchase needs (43+40)×50=4 150 (RMB).

Option 3: Joint purchase of 9 1 suit requires 9 1×40=3640 (RMB).

To sum up: because of 4980 & gt4 150 >3640, the two schools should unite and choose to buy 9 1 suit at one time according to 40 yuan, which is the most economical.