Answer:
there are 9 quarters and 19 dimes
Step-by-step explanation:
Let x be the number of dimes and y the number of quarters
-dimes: 0.1x
-quarters: 0.25y
-the total amount of coins : x + y = 28
=> x = 28 - y
We have the equation:
0.25y + 0.1x = 4.15
0.25y + 0.1(28 - y) = 4.15
0.25y + 2.8 - 0.1y = 4.15
0.15y = 1.35
y = 9
x = 28 - y
= 28 - 9
= 19
Answer:
Missing Number: 70,000,000
The answer is B.
Since ΔQRS ~ ΔXYZ, the value of tan(Q) is :
- ∠Q = ∠X
- tan(Q) = tan(X)
- tan(X) = 3/4
- tan(Q) = 3/4
If 25% of the people <em>are</em> vaccinated, then 75% of the people are <em>not</em> vaccinated. Of those not vaccinated, each has a 50% chance of contracting the disease. The probability that someone is both not vaccinated and contracts the disease is (0.75)(0.5)=0.375.
The probability that someone is vaccinated and contracts the disease is (0.25)(0.1)=0.025 (it is multiplied by 0.1 because if the vaccine is 90% effective, then there is a 10% chance someone that is vaccinated can contract the disease.
Add these together for the total: 0.375+0.025=0.4
There is a 40% chance that someone chosen at random will contract the disease.