The answer
(a) $417
(b)(i) $3842.60
(ii) $360
(c)(i) $363
(ii) $361.11
O-Level E-Math 2015 Paper 2 Question 3 · Verified worked solution by the Genius Plus Academy teaching team
What this question tests
This is Question 3 of the O-Level E-Math 2015 Paper 2. It tests wage + percentage bonus, in the Percentage & money in context area. It is worth 12 marks: (a) 2, (b) 2 + 2, (c) 3 + 3. It is a worded / diagram-based question, so open your Ten-Year Series (TYS) or the official paper at this question, then follow our full worked solution below.
(a) Earnings \(= 32 \times 10.50 + 0.06 \times 1350 = 336 + 81 = \$417\).
(b)(i) Deposit \(= \dfrac15 \times 3499 = \$699.80\); instalments \(= 24 \times 130.95 = \$3142.80\). Total \(= 699.80 + 3142.80 = \$3842.60\).
(ii) $342 is \(95\%\) of the price he paid: price \(= \dfrac{342}{0.95} = \$360\).
(c)(i) Amount \(= 1500(1.075)^3 = \$1863.45\); interest \(= 1863.45 - 1500 = \$363\) (nearest dollar).
(ii) Total in pounds \(= 185 \times 1.015 = \pounds 187.775\). Convert (since $1 = £0.52, divide by 0.52): \(\dfrac{187.775}{0.52} = \$361.11\) (nearest cent).
Answer: (a) $417
(b)(i) $3842.60
(ii) $360
(c)(i) $363
(ii) $361.11
Same structure, different numbers
Swap the constants, dress a quadratic as a length, hide a derivative inside an integral, and a student sees a brand new problem. The structure underneath is the same, and so is the method. Once a student can name the structure, a whole row of questions that look different start to open the same way.
That is where marks really leak: in choosing the method, not in the algebra that follows. We call it Lock and Key, name the lock, then the key follows.
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Genius Plus Academy · O-Level & IP Mathematics
Our O-Level E-Math tuition trains the same recognise-the-structure method these worked solutions show, taught by a team that has marked these papers for years. It runs within our weekly Secondary Math programme, Sec 1 to 4 and IP.
It is a wage + percentage bonus question from Percentage & money in context, worth 12 marks: (a) 2, (b) 2 + 2, (c) 3 + 3.
Yes. IP (Integrated Programme) schools teach the same O-Level Mathematics content; they just sequence it differently and set their own internal exams, so these worked solutions apply to IP students too.
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