The ratio here is 3:4.5
11 is not divisible by 3 so we can divide the ratio by 3 to find out how many pages Tanya types in the same time as Ingrid types one.
3:4.5 รท3 = 1:1.5
Now we have to multiply 1.5 by 11 as this is how many Ingrid has done. 11x1.5= 16.5
so Tanya will have typed 16.5 pages