NCERT Class XI Mathematics - Sequences and Series - Solutions
© examsnet.com
Question : 109
Total: 106
A manufacturer reckons that the value of a machine, which costs him Rs. 15625, will depreciate each year by 20%. Find the estimated value at the end of 5 years.
Solution:
Cost of machine = Rs. 15625
It will depreciate each year by 20%
∴ Cost of machine at the end of first year = Rs.( 15625 −
)
= Rs. (15625 – 3125) = Rs. 12500.
Cost of machine at the end of second year = Rs.( 12500 −
)
= Rs. [12500 – 2500] = Rs. 10000
Cost of machine at the end of third year = Rs.( 10000 −
)
= Rs. [10000 – 2000] = Rs. 8000
Cost of machine at the end of fourth year = Rs.( 8000 −
)
= Rs. [8000 – 1600] = Rs. 6400
Cost of machine at the end of fifth year = Rs.( 6400 −
)
= Rs. [6400 – 1280] = Rs. 5120.
It will depreciate each year by 20%
∴ Cost of machine at the end of first year = Rs.
= Rs. (15625 – 3125) = Rs. 12500.
Cost of machine at the end of second year = Rs.
= Rs. [12500 – 2500] = Rs. 10000
Cost of machine at the end of third year = Rs.
= Rs. [10000 – 2000] = Rs. 8000
Cost of machine at the end of fourth year = Rs.
= Rs. [8000 – 1600] = Rs. 6400
Cost of machine at the end of fifth year = Rs.
= Rs. [6400 – 1280] = Rs. 5120.
© examsnet.com
Go to Question: