The first question. There is a way to set an unknown number, assuming that the first number is X, the second number is Y, X: Y = 2: 3, y-x=6. Then solve the equation, the final answer is 24: 18.

,

39:26.

The second question, πD/πd=2.

So the diameter of the small circle is half that of the big circle, which is 4 cm.

The third question, football+basketball =20, football/basketball =7:3, which shows that football has 14 and basketball has 6. Suppose X footballs are bought later, then two footballs have the solution of (14+X): 20 = 4: 5.