Play =a

Good =b

Learning =c

Number =d

therefore

The single digit of 4d is equal to a.

Because 4a is less than 10.

therefore

A= 1 or 2

Because a= 1 cannot satisfy that the single digit of 4d is equal to a.

So a=2

So d=8 (because the 4d number is 2)

While 4b is less than 10.

So b= 1 or 2.

Because d=8 and 4d=32.

So b-3 equals 4c's single digits.

So b=2 is truncated (the condition of the previous line cannot be met).

So b= 1.

So the 4c number is 8.

So c=2 or 7.

Because b= 1

So c is greater than or equal to 4.

So c equals 7.

Empirical calculation

2 178*4=87 12

To sum it up

Hard =2 178