Using the rule of 72, t=72/r, how long will it take for the principal to double with an annual compound interest rate of 6%?

12 years

Step-by-step explanation:

r = compound interest rate in percent

t = doubling time in years

t = (72percent years)/(6 percent) = 12 years

As a curious cultural fact, there is a connection between the 72 and the fact that ln(2) = 0.69314718055. The constant is 69.3 for continuous compounding...

2. angles qrt and qst both measures 156 degrees.

step-by-step explanation:  

we have been given a diagram of a circle and we are told that measure of arc qvt is 156 degrees.  

we can see from our given diagram that angle qrt and angle qst subtends to arc qvt.

since we know that angles subtended by the same arc at the circumference are always equal.

by angle subtended by same arc theorem, measure of angle qrt and angle qst will be equal to the measure of arc qvt.

therefore, angles qrt and qst both measures 156 degrees and 2nd statement is the correct choice.

let y equal to

the total fare and x is the mile of taxi ride. so the equation is

y = 0.55x + 1.75

since susie has

$10 to spend for a taxi cab, so he can have

10 = 0.55x +

1.75

x = 15 miles of

taxi ride

so the system of

inequality is

10 < 0.55x +

1.75

x > 2