Answer:
Amount of Niobium-91 initially
= 300/91 =3.2967mol
2040 years = 3 ×680 = 3 half-lives
therefore, amount left = 0.4121mol
mass of Niobium-91 remaining = 0.4121 ×91 =37.5g
Please give brainliest
Answer:
The unit rate in miles per hour = <em>1.4 miles/hr</em>
Step-by-step explanation:
Given that:
Distance walked by Boardman family = Two over five of a mile = 
Time taken by Boardman family = Two over seven of an hour = 
To find:
The unit rate in the miles per hour = ?
Solution:
Formula for the rate or the speed can be given as:

Putting the values:

So, the unit rate in miles per hour = <em>1.4 miles/hr</em>
Robins basket is heavier.
Teds basket: 5x7.25=36.25
Robins basket: 6x6.25=37.5
37.5-36.25= 1.25
It is heavier by 1.25 ounces or 1 and 1/4 ounces
Answer:
5.61; 8.5 %
Step-by-step explanation:
Tax = $1.87 per $22 meal
For a $66 meal,
Tax = 66 × 1.87/22
Tax = 3 × 1.87
Tax = $5.61
=====
Tax rate = 1.87/22 × 100
Tax rate = 0.085 × 100
Tax rate = 8.5 %
15x=180
x=12
hope this helps