#1: what percent of 78 is 16?

#2: what is 79% of 55?

1.   487.5%

2.  43.45

Step-by-step explanation:

Remember the formula for a proportion: ((part)/(whole)) = ((percent)/(100))

1.

The part is given, 78, and the whole is given, 16.

Set up a porportion:

78/16 = percent/ 100

Simplify:

39/8 = percent /100

Cross products

39/8 = percent/100

8percent = 3900

Inverse operations

8percent = 3900

/8     /8

percent = 487.5

487.5%

2.

The percent is given, and the whole is given.

Set up a proportion:

part/55 = 79/100

Cross products

part/55 = 79/100

100part = 4345

Inverse operations

100part = 4345

/100    /100

part = 43.45

43.45

The solution is  (2,6)

Step-by-step explanation:

Let

x-----> the number of hours to change a fuel injection unit

y-----> the number of hours to change a transmission

we know that

5x+10y=70 -----> equation A

8x+8y=64 -----> equation B

Solve the system of equations by graphing

Remember that the solution of the system of equations is the intersection point both graphs

The solution is the point (2,6)

see the attached figure