If you are not being put through these by a potential sponsor I would not even try to fool the test: they are for your benefit only. If you do very badly, seriously consider another career, and discuss the results with the provider. The only reason I can see for taking them in this case is for your own peace of mind. If schools insist on you passing before taking their course I would suspect them of a desire to create a "sausage factory" of narrowly-defined individuals in one end pilots out of the other (many people who have not passed the tests have perfectly adequately taken an ATPL course and carried on to be successful pilots, so I do not see it as your FTO's job to select who can be a pilot). This does not suggest you will get much personal attention!