Sum and difference problem? The larger external term is: (37+ 13) divided by 2=25.

The smaller external term is 37-25= 12,

If the two internal terms are x and y respectively, the proportional formula is 25\x=y\ 12=2.5.

X= 10，y=30，

So the proportional formula is 25 10 = 30 12.

2 method 1

The ratio of Party A to Party B is 8:7. 1\4 After shipment, the ratio of Party A to Party B is 6 :7. If Party A has 6 shares and Party B has 7 shares of grain.

At this time, B is five tons more than A, so A grain should be five tons.

Then the original 8 portions of grain in warehouse A should be 5*8=40 tons.

Method 2

Equation can be listed, assuming that the original stored grain in A is 8 tons, then the stored grain in B is 7 tons, and the equation is

7x-8x( 1- 1\4)=5

7x-6x=5

x=5

So warehouse A initially stores 8x=40 (tons).