A=12
120% of a =80% of b
120%a = 80%b
120a/100 = 80b/100
Divide through by 100
120a = 80b
Divide through by 80
120a/80 = b
But a=12
120x 12/80 = b
18 = b
b = 18
a+b = 12 + 18 = 30
Answer:

Explanation:
Build your conversion factors using the conversion table:
From the prefixes used in the metric system, you know that 1 deciliter = 0.100 liters. Then:
Arrange the expression to simplify the units and convert from cups to deciliters:
Round to the nearest tenth: 0.2 deciliter.
Answer: 9 boys
Explanation:
3/11= x/33
11x= 99
x=9
Answer:
a) A. The population must be normally distributed
b) P(X < 68.2) = 0.7967
c) P(X ≥ 65.6) = 0.3745
Step-by-step explanation:
a) The population is normally distributed having a mean (
) = 64 and a standard deviation (
) = 
b) P(X < 68.2)
First me need to calculate the z score (z). This is given by the equation:
but μ=64 and σ=19 and n=14,
and 
Therefore: 
From z table, P(X < 68.2) = P(z < 0.83) = 0.7967
P(X < 68.2) = 0.7967
c) P(X ≥ 65.6)
First me need to calculate the z score (z). This is given by the equation:
Therefore: 
From z table, P(X ≥ 65.6) = P(z ≥ 0.32) = 1 - P(z < 0.32) = 1 - 0.6255 = 0.3745
P(X ≥ 65.6) = 0.3745
P(X < 68.2) = 0.7967