Answer:
The age of Mr. Collins is 30 years and
The model which represent the problem is, The age of Mr. Collins is 3 × 10
Step-by-step explanation:
Given as :
The age of Adam = 10 years
The age of Mr. Collins = x years
The age of Mr. Collins = 3 times the age of Adam
Or, x = 3 × The age of Adam
Or, x = 3 × 10
∴ x = 30
So, The age of Mr. Collins = x years = 30 years
The model which represent the problem is, The age of Mr. Collins = 3 × 10
Hence The age of Mr. Collins is 30 years and
The model which represent the problem is, The age of Mr. Collins = 3 × 10
Answer
Answer:

Step-by-step explanation:
we know that
The surface area of a sphere is equal to

we have

substitute


Answer: 0.000021 in scientific notation is
2.1 × 10-5
Step-by-step explanation:
All numbers in scientific notation or standard form are written in the form
m × 10n, where m is a number between 1 and 10 ( 1 ≤ |m| < 10 ) and the exponent n is a positive or negative integer.
To convert 0.000021 into scientific notation, follow these steps:
Move the decimal 5 times to right in the number so that the resulting number, m = 2.1, is greater than or equal to 1 but less than 10
Since we moved the decimal to the right the exponent n is negative
n = -5
Write in the scientific notation form m × 10n
= 2.1 × 10-5
Therefore,
2.1 × 10-5 is the scientific notation form of 0.000021 number and 2.1e-5 is the scientific e-notation form for 0.000021
** Hope this helps you! Good Luck!