Question

what is the solution to (3 × 10^2) x (5 × 10^5), written in scientific notation?
A.1.5 × 10^8
B.15 × 10^8
C.1.5 × 10^7
D.15 × 10^7


ben spent 2/3 of his allowance on video games. what is the fraction of his allowance expressed as a decimal.
A.0.6
B.0.7
C.0.16
D.0.17

My answers
B
A

Answer 1

Answer:

1 - Option A is correct i,e $1.5 \times 10^8$

2- Option A is correct, 0.6

Step-by-step explanation:

Given: $(3 \times 10^2) \times (5 \times 10^5)$

You have to do the following steps to get the answer:

• First multiply the two coefficients.
• Next, multiply the two powers of ten by adding their exponents.
• then, finally, combine your two answers and convert to scientific notation.

$(3 \times 10^2) \times (5 \times 10^5)$

Apply the following steps;

$(3 \times 5) \times ( 10^2 \times 10^5)$

$(15) \times ( 10^{2+5})$

$(15) \times ( 10^7)$

Convert to scientific notation as;

$1.5 \times 10^8$

Therefore, the solution to $(3 \times 10^2) \times (5 \times 10^5)$ is,  $1.5 \times 10^8$

Given the statement: Ben spent 2/3 of his allowance on video games.

To find the fraction of his allowance as a decimal.

Convert a fraction number into decimal.

$\frac{2}{3}$

Multiply top and bottom by 33 ;

$\frac{2 \times 33}{3 \times 33}= \frac{66}{99}$

Now, 99 is nearly 100, so let us write down 66 with the decimal point 2 spaces from the right (because 100 has 2 zeros) i.e,

0.66 (accurate to only 2 places)

Therefore, fraction number $\frac{2}{3}$ of his allowance expressed as a decimal is, 0.6