Answer:
Option D - 25
Step-by-step explanation:
Given : A sample of rock is found to contain 100 grams of a parent isotope.
To find : How many grams of the parent isotope will remain after two half-lives.
Solution : A sample of rocks contain parent isotope = 100 gram
After one half life of the parent isotope i.e. divided by 2
After two half lives of the parent isotope means again divide one-half life by 2
Which means 25 gram of the parent isotope will remain after two half lives.
Therefore, Option D is correct -25
Given:
The price of a doll = $35
Sales tax = 6%
To find:
The tax amount that a customer will pay on one doll.
Solution:
The price of doll is $35 and the sales tax is 6%, so the tax amount on a doll is 6% of 35.
Therefore, the tax amount that a customer will pay on one doll is $2.1.