Hi Ayushya.. :)
We dont need to use t-test or anything here.
Just use the definition/meaning of type1 and type2 errors.
Type1 error is rejecting the Null given that its true.
It means while finding type1 error, you need to take Null to be true and then, use the test procedure of rejecting null (which is in this case x<k).
So, we've : Type1 error = Integral (2x)dx from 0 to k . And its given Type1 error = 0.09
⇒ Integral (2x) from 0 to k = 0.09
⇒ k =0.3
Now,Type2 error is accepting the null given that alternate hypothesis is true.
So, take Alternate hypothesis to be true and then, use the test procedue of accepting the null (which is x>k).
So, we've: Type2 error = Integral (2-2x)dx from 0.3 to 1
= 0.49
:)