Answer:

60 pupils

Step-by-step explanation:

12/N = 20/100

(12)(100) = (20)(N)

1,200 = 20N

1,200/20 = 20N/20

60 = N

checking:

12/60 = 0.2 or 20%

Answer:

12 pupils got 90 and 20% of the pupils is 12

20% × 5=100%

12 × 5=60

So there for in that class there are 60 pupils