Find the amount of the interest that Mandzur must pay. Give your answer correct to the nearest 100 KHR.

Write down your answer to part (a) in the form $a \times {10^k},{\text{ where }}1 \leqslant a < 10,{\text{ }}k \in \mathbb{Z}$.

$FV = 900000{\left( {1 + \frac{{15}}{{12 \times 100}}} \right)^{24}}$     (M1)(A1)

Note: Award (M1) for substitution in the compound interest formula (either $FV$ or interest), do not penalize if $–PV$ not seen.

Award (A1) for correct substitution.

 

OR

${\text{N}} = 2$

${\text{I%  = 15}}$

${\text{PV = 900}}\,{\text{000}}$

${\text{P/Y}} = 1$

${\text{C/Y}} = 12$     (A1)(M1)

Note: Award (A1) for ${\text{C/Y}} = 12$ seen, (M1) for other correct entries.

 

OR

${\text{N}} = 24$

${\text{I%  = 15}}$

${\text{PV = 900}}\,{\text{000}}$

${\text{P/Y}} = 12$

${\text{C/Y}} = 12$     (A1)(M1)

Note: Award (A1) for ${\text{C/Y}} = 12$ seen, (M1) for other correct entries.

 

${\text{interest = 321615.945}}$     (A1)

$= 312\,600\;\;\;{\text{(KHR)}}$     (A1)(ft)     (C4)

 

Notes: Award the final (A1) for the correct rounding of their unrounded answer.

If final amount is $1 212 600$ and working is shown award (M1)(A1)(A0)(A1)(ft).

Award (A2) for $(FV = )\ 1212600$ if no working is seen.

$3.126 \times {10^5}$     (A1)(ft)(A1)(ft)     (C2)

Notes: Award (A1)(ft) for their $3.126$ $(3.13)$, (A1)(ft) for $\times {10^5}$.

Follow through from part (a).

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