A.)Rachel should have 6 second class tramps. Because if you do the equation 6+6+6 you get 18 (the number of first class stamps she has)
2.)Add 6 to 18 to get your answer :)
Volume of a sphere with radius of 70 feet is:

where r is that radius
Because we need quarter sized tank of that radius we need to divide formula for volume by 4
Than we get:

V = 359188,76
Rounded:
V = 359189
Δ DUM Δ MAP
hypotenuse: 15 2y-3
short leg: 12 0.5x + 6
y = 9 ⇒ 2(9) - 3 = 18 - 3 = 15 Congruent with the hypotenuse of Δ DUM
x = 12 ⇒ 0.5(12) + 6 = 6 + 6 = 12 Congruent with the short leg of Δ DUM
SAS postulate states that two triangles are congruent if 2 of its sides and 1 angle have equal measure. Both the hypotenuse and short leg are equal in measure. Thus, both triangles are congruent with each other.
Answer:
Bottom right graph
Step-by-step explanation: