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\ 28-Jan-2025 Surender Prajapati Proof-6 Reader’s Sign _______________________ Date __________

11. The selling price of 12 gift articles is the same as the cost price of 15 articles. Find the gain or loss
percent.

12. Raman borrowed `20,000 from a bank at 8% rate of interest per annum for 18 months. Aman borrowed
the same sum of money at 12% per annum for 219 days. Who paid more interest, and how much?

13. A farmer borrowed `30,000 from a bank on 1st March, 2020 at 5%. He cleared the debt on 31st
December, 2024 by giving the bank `32,000 and a goat. What is the value of the goat?
14. An NGO donates `10,00,000 to a school, the interest on which is to be used for awarding four
scholarships to students obtaining first four positions in the school examination every year. If the
donation earns an interest rate of 18 per cent per annum and the values of the second, third, and
fourth scholarships are `50,000, `30,000, and `25,000, respectively, find out the value of the first
scholarship. CompetenCy Based Question

15. Our home planet Earth’s interior is generally divided into
three major layers: the crust, the mantle, and the core.
Further mantle is divided into two layers—the upper Case study
mantle and the lower mantle. Similarly, the core is also
divided into two layers—outer core and inner core. The
crust is the outermost layer, and the core is the innermost
layer of the earth. The approximated radius of the Earth
is 6435 km.

Based on the above information, answer the following questions:
(a) If the thickness of the crust is 35 km, what approximated percentage of the Earth’s radius
is the crust?
(b) If the thickness of the lower mantle layer is 2200 km, then express it as a percentage of
the Earth’s radius.
(c) If the total thickness of the core is 3500 km and outer core is 2300 km. Express the thickness
of the outer core as a percentage of the whole core.

Brain Sizzlers

Sathvik buys items worth `300 from a shop. He gives a `500 note to the shopkeeper. The shopkeeper gets the
change from the next shop and keeps `300 for himself and returns `200 to him. Later, the shopkeeper of the
next shop comes with the `500 note saying it is ‘duplicate’ and takes his money back. If the shopkeeper had sold
the items with zero profit, find the loss that the shopkeeper suffered.

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