Question

There is an average of 3.5 x 10^−2 kilograms of dissolved salt in each liter of seawater. The South China Sea contains approximately ​ 9.88 x 10^18 ​ liters of seawater. About how many kilograms of dissolved salt are in south china sea Enter your answer, in scientific notation, in the boxes. __×10__ kg

Answer 1

Answer:

$3.458\times10^{17}$ kg

Step-by-step explanation:

It has been given that in 1 liter of seawater, the amount of dissolved salt is $3.5\times10^{-2}$kg

Let x kg of salt is dissolved in $9.88\times10^{18}$ liters of seawater.

Thus, we have

$\frac{1}{3.5\times10^{-2}}=\frac{9.88\times10^{18}}{x}$

On cross multiplying, we get

$x=3.5\times10^{-2}\times9.88\times10^{18}\\\\x=34.58\times10^{16}$

In scientific notation,

$x=3.458\times10^{17}$

Thus, $3.458\times10^{17}$ kg of salt is dissolved.

Answer 2

Alright, since there's 3.5*10^(-2) of salt for each liter of seawater, that means that for each liter added we add that to it, meaning that we multiply the amount of salt per liter by the total amount of liters, resulting in 3.5*9.88*10^(-2)*10^18=34.58*10^16 (by adding -2 and 18 we get 16). Since we only want 1 number in front of the decimal (that's not a 0) for scientific notation, we can move the decimal one spot to the left to make it 3.458. However, we can't simply move the decimal without changing the exponent - since we moved it one to the left, we must increase the power from 16 to 17 (conversely, if it moved to the right, we'd decrease the power), resulting in 3.458*10^17