# RS Aggarwal Class 8 Math Second Chapter Exponents Exercise 2B Solution

## EXERCISE 2B

**(1) Write each of the following numbers in standard form: **

(i) 57.36 = 5.736 × 10

(ii) 3500000 = 3.5 × 10^{6}

(iii) 273000 = 2.73 × 10^{5}

(iv) 168000000 = 1.68 × 10^{8}

(v) 4630000000000 = 4.63 × 10^{12}

(vi) 345 × 10^{5} = 3.45 × 10^{7}

**(2) Write each of the following numbers in usual from:**

**(3) (i) The height of Mount Everest is 8848 m. write it in standard form. **

Solution: the height of Mount Everest = 8848 m

= (8.848 × 1000) m = (8.848 × 10^{3}) m.

**(ii) The speed of light is 300000000 m/sec. Express it in standard form. **

Solution: The speed of light = 300000000 m/sec

= (3 × 100000000) m/sec = (3 × 10^{8}) m/sec

**(iii) The distance from the earth to the sun is 149600000000 m. Write it in standard form.**

Solution: The distance between earth and sun = 149600000000 m

= (1.496 × 100000000000) m = (1.496 × 10^{11}) m

**(4) Mass of earth is (5.97 × 10 ^{24}) kg and mass of moon is (7.35 × 10^{22}) kg. What is the total mass of the two?**

Solution: The total mass = {(5.97 × 10^{2} × 10^{22}) + (7.35 × 10^{22})} kg

= {(597 + 7.35) × 10^{22}}kg = 604.35 × 10^{22 }kg

**(5) Write each of the following numbers in standard form:**

**(7) Write each of the following numbers in usual form: **