Let us assume the number of stamps of 20p and 25p be x and y respectively

According to the question, we have

x + y = 47 …(i)

0.20x + 0.25y = 10

Also, 4x + 5y = 200 …(ii)

From equation (i), we have

y = 47 – x

Now, putting the value of y in (ii), we get

4x + 5 (47 – x) = 200

4x – 5x + 235 = 200

x = 235 – 200

x = 35

Now putting the value of x in (i), we get:

35 + y = 47

∴ y = 47 – 35

y = 12

Hence, the number of 20p stamps are 35 and the number of 25p stamps are 12