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

1 - Option A is correct i,e
`1.5 * 10^8`

2- Option A is correct, 0.6

Explanation:

Given:
`(3 * 10^2) * (5 * 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 * 10^2) * (5 * 10^5)`

Apply the following steps;

`(3 * 5) * ( 10^2 * 10^5)`

`(15) * ( 10^(2+5))`

`(15) * ( 10^7)`

Convert to scientific notation as;

`1.5 * 10^8`

Therefore, the solution to
`(3 * 10^2) * (5 * 10^5)` is,
`1.5 * 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.

`(2)/(3)`

Multiply top and bottom by 33 ;

`(2 * 33)/(3 * 33)= (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
`(2)/(3)` of his allowance expressed as a decimal is, 0.6