(1800 divided by 3/5) times (5/ 12)= 1250.

3. 100 divided by (1-4/5)=500.

4. Let Party A and Party B bring X and Y yuan respectively, and there will be equations.

{x+y= 108.................①

( 1-2/4)x=( 1-80%)y..②

② The simplified formula is:1/2x-1/5y = 0 → 5x-2y = 0.

Substitute ①: y= 108-x into ②: 5x-2( 108-x)=0.

5x-2 16+2x=0

7x=2 16

x=2 16/7

Then: y =108-216/7 = 540/7.

5.( 10/2) *3. 14 squared times (9.2-8)=94.2.

6. Suppose a * * * has X books, then:

(x-0.25 x- 140):(0.25 x+ 140)= 1:5

5(x-0.25 x- 140)= 0.25 x+ 140

5x- 1.5x= 140+700

x=240

7. If the set price is X and the original price is x-50, then:

[0.75 x-(x-50)]* 10 =[x-30-(x-50)]* 12

x= 104

Hanma Chen Jue An Waizhen won the bid for Qingshi yangjin Kaitai Fu Min Zhengqing Exhibition.