14+(x- 14)*3/7=50%x

Find out which apples are sold on the third day after being multiplied by 50%.

2. Assumption: Warehouse B has X tons of grain;

x- 15 = x *( 1-25%)+ 15

Found warehouse b, naturally found warehouse a.

3. Suppose Party A has X tons of coal and Party B has 72-x tons of coal:

x *( 1-4/5)=(72-x)*( 1-75%)

4. Assume that barrel A has X kilograms of oil and barrel B has 90-x kilograms of oil:

3/4x divided by (90-x)+3/4x= 1/2.