Answer: 
Step-by-step explanation:
Given
New mail carrier takes 4 hours for delivery i.e.
New mail carrier completes 
part of work in 1 hour
Old mail carrier takes 3 hours for delivery i.e.
mail carrier completes 
part of work in 1 hour
If they work together, they complete the work in x hours i.e.
7 5 35
-- X -- = -----
1 6 6
hope it helps
7 =7/1
Multiplying Fractions is easy . numerator times numerator and denominator times denominator. then simplify if possible
Must be 16 and 21 because we can see
30 and 70 has 10 as factor
24 and 44 has 2 as factor
12 and 30 has 2 as factor and all those factors are greater than one
The two parallel bases b1 and b2 are
b1 = 12
b2 = 9
the order of which base you pick doesn't matter
The height is h = 10 and it's perpendicular to each base.
The area is...
A = (1/2)*h*(b1+b2)
A = (1/2)*10*(12+9)
A = (1/2)*10*(21)
A = 5*21
A = 105
Final Answer: B) 105 square centimeters
