4 digit palindromes must be of form abba, so being required that you use both numbers, you only have two: 1221 and 2112
Answer: The number of child tickets is 85 and the number of adult tickets is 95.
Step-by-step explanation:
Let C = Number of child tickets
A = Number of adult tickets.
As per given, we have
C+A=180 (i)
7C+13A=1830 (ii)
Multiply 7 to both sides of equation (ii), we get
7C+7A=1260 (iii)
Eliminate (iii) from (ii) , we get

Put value of y in (i), we get
C= 85
Hence, the number of child tickets is 85 and the number of adult tickets is 95.
Newton's Law of Cooling
Tf=Ts+(Ti-Ts)e^(-kt) where Tf is temp at time t, Ts is temp of surroundings, Ti is temp of object/fluid. So we need to find k first.
200=68+(210-68)e^(-10k)
132=142e^(-10k)
132/142=e^(-10k)
ln(132/142)=-10k
k=-ln(132/142)/10
k≈0.0073 so
T(t)=68+142e^(-0.0073t) so how long until it reaches 180°?
180=68+142e^(-0.0073t)
112=142e^(-0.0073t)
112/142=e^(-0.0073t)
ln(112/142)=-0.0073t
t= -ln(112/142)/(0.0073)
t≈32.51 minutes
Answer:

Step-by-step explanation:
Use this formula,

where n is the amount of even intergers, a is the starting term, d is the common difference.
- the amount of even intergers from 2 to 200 is 100
- The starting number is 2
- The common difference is 2



