Juan broke a cell sample into 11 batches, each weighing 1.8 x 10^-8

grams. How much did the original sample weigh? Use scientific notation to express your answer.

1 answer

To find the total weight of the original cell sample, you can multiply the weight of each batch by the number of batches.

Each batch weighs \(1.8 \times 10^{-8}\) grams, and there are 11 batches.

\[ \text{Total weight} = \text{weight of each batch} \times \text{number of batches} \]

\[ \text{Total weight} = (1.8 \times 10^{-8}) \times 11 \]

Now, calculate \(1.8 \times 11\):

\[ 1.8 \times 11 = 19.8 \]

Next, we can express \(19.8\) in scientific notation.

To convert \(19.8\) to scientific notation, we can express it as \(1.98 \times 10^1\) (since moving the decimal point one place to the left increases the exponent of 10 by 1).

Now combine this with the \(10^{-8}\):

\[ \text{Total weight} = 1.98 \times 10^1 \times 10^{-8} \]

When multiplying exponentials, we add the exponents:

\[ 1.98 \times 10^{1 + (-8)} = 1.98 \times 10^{-7} \]

Thus, the original sample weighed:

\[ \boxed{1.98 \times 10^{-7}} \text{ grams} \]