Answer:
it's d because it's correct
Step-by-step explanation:
140 tickets sold at the door
Step by Step Explanation:
x = tickets sold in advance
y = tickets sold at the door
We use the formula ax+by=c and a+b=c
x + y = 514
17x + 20y = 9158
y = 514 - x
17x + 20(514 - x)
17x + 10,280 - 20x = 9,158
-3x + 10,280 = 9,158
-3x = -11222
x = 374
This is for tickets sold in advance so we need to find y
374 + y = 514
y = 140
140 tickets were sold at the door
Answer:
<u>30 gallons solution 4% and 10 gallons solution 8%</u>
Step-by-step explanation:
<h3>x•4%+y•8%=40•5% </h3>
<em><u>4x+8y=40•5 and x+y=40</u></em>
x=40-y
4(40-y)+8y=200
160-4y+8y=200
4y=200-160
4y=40 => y=10 (gallons solution 8%)
=> x=40-10=30 (gallons solution 4%)
30 gallons solution 4% and 10 gallons solution 8%
To solve this we are going to use the half life equation

Where:

is the initial sample

is the time in years

is the half life of the substance

is the remainder quantity after

years
From the problem we know that:



Lets replace those values in our equation to find

:




We can conclude that after 1600 years of radioactive decay, the mass of the 100-gram sample will be
91.7 grams.