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nism-series-xb-leisure-expense-compounding-27-years[ INVESTMENT ADVISER (LEVEL 2) ]

In Case 4, Mr. Smart's social occasion and leisure travel expenses start at Rs. 1,00,000 p.a. at age 60 and inflate at 6% p.a. What will this annual leisure expense grow to by the final retirement year at age 87 (Year 27)?

[ A ]Rs. 2,62,000
[ B ]Rs. 4,82,235[ CORRECT ]
[ C ]Rs. 3,50,000
[ D ]Rs. 6,10,500
Takeaway

Compounding Mr. Smart's leisure expense of Rs. 1,00,000 at 6% inflation over 27 years grows it to Rs. 4,82,235 by the final retirement year, so option B is correct.

Derivation
FV = PV x (1 + r)^n = Rs. 1,00,000 x (1.06)^27. The compounding factor (1.06)^27 equals approximately 4.822349, giving FV = Rs. 4,82,235. This tests long-horizon compounding discipline over a genuinely long 27-year period, where small differences in method (simple versus compound interest, or a slightly wrong rate) produce dramatically different results — exactly the kind of divergence that makes correctly modelling multi-decade retirement expense inflation so consequential in practice.
Why the others fail
A — Rs. 2,62,000
Calculated using simple interest: Rs. 1,00,000 x (1 + 0.06 x 27), which drastically understates the true compound growth over 27 years.
C — Rs. 3,50,000
This is an arbitrary linear estimate that does not correspond to applying the FV formula with the stated 6% inflation rate over 27 years.
D — Rs. 6,10,500
Assumes an 8% inflation rate instead of the stated 6%, overstating the compounded leisure expense figure for Year 27.