# NCERT Class 8 Mathematics Solutions: Chapter 8 – Comparing Quantities Exercise 8.3 Part 6 (For CBSE, ICSE, IAS, NET, NRA 2022)

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**Question: 11** In a laboratory, the count of bacteria in a certain experiment was increasing at the rate of 2.5 % per hour. Find the bacteria at the end of 2 hours if the count was initially 5,06, 000.

**Answer**:

Here, Principal (P) = 5,06, 000 Rate of Interest (R) = 2.5 % , Time (n) = 2 hours

After 2 hours, number of bacteria

Amount (A)

Hence, number of bacteria after two hours are **531616.25**

**Question: 12** A scooters were bought at ₹ 42,000. Its value depreciated at the rate of 8 % per annum. Find its value after one year.

**Answer**:

Here, Principal (P) = ₹ 42,000, Rate of Interest (R) = 8 % , Time (n) = 1 years

Amount (A)

Hence, the value of scooter after one year is **₹ 45,360**