# Important Questions for Class 8 Chapter 12-Exponents and Powers

The set of important questions carries step-by-step explanation and solution to the given questions. You just need to go through them and prepare well for your exams. The PDF we provided is absolutely free. So, Download your free PDF now and start practicing!

Important questions based on NCERT syllabus for Chapter 12-Exponents and Powers:

Question 1: Simplify :(−2/3)^8 × (−2/3)^5 × 72^9
Solution:
(−2/3)^8 × (−2/3)^5 × 72^9
= (−2/3)^{(8+5)} × 3^6
= (−2/3)^{(13)} × 3^6
= −(2^13/3^7)

Question 2: Simplify : [{(−5)^5 × (−5)^{−10}} ÷ 25] × 10^5
Solution:
[{(−5)^5 × (−5)^{−10}} ÷ 25] × 10^5
[{(−5)^{(5−10)}} ÷ 25] × 10^5
[(−5)^{−5} × 2^{−5}] × 10^5
[(−1)^{−5} (5)^{−5} × 2^{−5}] × 10^5
[−(10)^{−5}] × 10^5
= −1

Question 3: Mass of A is 9.97×10^{24}kg and mass of B is 6.35×10^{22}kg. What is the total mass?
Solution:
Total mass = 9.97 × 10^{24}kg + 6.35 × 10^{22} kg
= 997 × 10^{22} + 6.35 × 10^{22}
= (997 + 6.35) × 10^{22}
= 1003.35 × 10^{22} kg
= 1.00335 × 1025 kg

Question 4: If 15625 = (x)^2 = 5^(y) . Find the value of x and y.
Solution:
15625 = (x)^2 = 5^(y)
Prime factorisation of
15625 = 5 × 5 × 5 × 5 × 5 × 5 = 5^6 = 125^2
x = 125
y = 6