Question

In 8 days,the earth picks up 6.4 ×10 7kg of dust from atmosphere. How much dust will it pick up in 15 days

Answer 1

Answer:  The earth picks up $1.2\times 10^ 8kg$   in 15 days

Step-by-step explanation:

Earth picks dust from atmosphere in 8 days= $6.4\times 10^7kg$

So by unitary method

Earth picks dust from atmosphere in 1 day = $\dfrac{6.4\times 10^7}{8} = 0.8\times 10^7kg$

Earth picks dust from atmosphere in 15 days

$=0.8\times 10^7kg \times 15 = 12\times 10^7 = 1.2\times 10^ 8kg$

Hence, the earth picks up $1.2\times 10^ 8kg$  in 15 days

Answer 2

Answer:

Answer: The earth picks up 1.2\times 10^ 8kg1.2×10

8

kg in 15 days

Step-by-step explanation:

Earth picks dust from atmosphere in 8 days= 6.4\times 10^7kg6.4×10

7

kg

So by unitary method

Earth picks dust from atmosphere in 1 day = \dfrac{6.4\times 10^7}{8} = 0.8\times 10^7kg

8

6.4×10

7

=0.8×10

7

kg

Earth picks dust from atmosphere in 15 days

=0.8\times 10^7kg \times 15 = 12\times 10^7 = 1.2\times 10^ 8kg=0.8×10

7

kg×15=12×10

7

=1.2×10

8

kg

Hence, the earth picks up 1.2\times 10^ 8kg1.2×10

8

kg in 15 days