Maths Qs - Cambridge Question

Question

Hey guys, been looking at this question for a while now. Was supposed to get it done in under 2 mins but it has been significantly longer than that - Any suggestions?

My brain is absolutely fried atm so I can't spend much longer on maths - I feel like im missing something out here. Would love a fresh perspective on this qs from you guys!

Joel Runevic · Accepted Answer

Hey @Apaul466 ,  Keep questions like this coming! I am assuming that this is the Cambridge Engineering Admissions Test and so it is non-calculator right?

Joel Runevic · Answer

@Apaul466 No worries.  Exactly that; your last statement is correct and is the reasoning behind my answer.

Apaul466 · Answer

@Joel Runevic You've got the correct answer but I am unsure about the method: Could you explain the QM/RS line of method and how that is equal to 4/5.

Is it because once you split the isosceles triangle in half to form two right-angled triangles, these smaller triangles are similar to RST and PQR triangles?

Thanks tho!

Joel Runevic · Answer

I assume you are asleep and I assumed that it was non-calculator. I have come up with a solution but considering it is midnight, I am not too confident. Let me know if the answer is right (if you know what the answer is that is).