It depends on the exam. One exam where it was totally possible was the EEE aero MAT for imperial college London. They have retired it since but i got about 50% (i know someone who got an interview with a negative score) because whenever the answer was a function, i could plug the function into the question ratger than do it from first principles (eg differential equations).
I spent £100 on an advert asking people to pay me on ko-fi and made £250