ElectricPavlov

= .000000000415    Is that what you were wanting to know??

20% is 20/100         20% of 360   is     360 x 20/100 = 72 runners in that age bracket

For friend...hair starts at 4 inches    this is 'b'  in    y = mx + b

so for friend   hair length = y = mx + 4          friend's hair grows 6.5 - 4 = 2.5 inches in 5 months = .5 inches/month

    so t = mx + b becomes         Hair length:     y = .5 x +4          where x is months

Similarly for cousin   'b' = 7   and   m = (9-7")/5months = .4    y = .4x + 7  

First ...how many cranes does she have left to make?   1000 - 304 Cranes

Second ...how many can she make per day?   8 cranes/day

Divide First by Second

(1000-304)cranes / (8 cranes/day) = (1000-304)/ 8  days     = 87 days

This is a RIGHT triangle (because one angle = 90 degrees)

Side AB is the hypotenuse ( if it was one of the legs it would have "C" in its name)

Side BC is the ADJACENT leg to angle B

COSINE = ADJACENT / HYPOTENUSE

COSINE B = 4/20.1

COS^-1   (4/20.1) = B = 78.52 degrees

This just equals    (1x1x1) / (2x2x2)  = 1/8

OR   this also equals (1/2)^3 = 1/8

$12.71 is to 106% as x is to 100%  ratio

$12.71/106% = x / 100%    Multiply both sides by 100%

x= original price of book =  $11.99

Here is a quick sketch:

This question was asked the other day     answer was   27 pi    I believe......

There are multiple ways to solve this....here is a graphical one

@ t=0  the dolphin jumps and grabs air at 6ft above the water  ....then dives to a maximum depth 24.6 M at t= 17.5 s

and resurfaces at t= 33.2 seconds