The Crews family went on a day trip to Nashville. For lunch they paid $7.50 for each adult meal and $5 for each child meal for a total of $65. For dinner the family paid $10.50 for each adult meal and $5 for each child meal for a total of $77. How many adults and how many children were on the trip?

Number of adult were on the trip = 4

Number of child were on the trip = 7

Step-by-step explanation:

Let the Number of adult were on the trip = x

Let the Number of child were on the trip = y

As given,

For lunch they paid $7.50 for each adult meal and $5 for each child meal for a total of $65.

⇒7.50x + 5y = 65            ...........(1)

Also,

For dinner the family paid $10.50 for each adult meal and $5 for each child meal for a total of $77.

⇒10.50x + 5y = 77            ...........(2)

Now,

Subtract equation (2) from equation (1) , we get

10.50x + 5y  - ( 7.50x + 5y ) = 77 - 65

⇒10.50x + 5y  - 7.50x - 5y  = 12

⇒10.50x - 7.50x  = 12

⇒3x = 12

⇒x = = 4

⇒x = 4

Now,

Put the value of x in equation (2) , we get

10.50(4) + 5y = 77

⇒42 + 5y = 77

⇒5y = 77 - 42

⇒5y = 35

⇒y = = 7

⇒y = 7

∴ we get

Number of adult were on the trip = x = 4

Number of child were on the trip = y = 7

Cost of 7 gallons=$24.50

Cost of 1 gallon=24.50/7=3.5

Cost of 15 gallons=15*3.5=52.5

Cost of 15 gallons will be $52.5

The total nom of  code that can be used is equal to 5+3 = 8

The answer is in the image 

y=2x+15

where y=Value of coin

x=Age in years

Value of coin after 19 years=2*19+15

=$53

Therefore, Value after 19 years=$53

F=ma

where F=force

m=mass

a=acceleration

Here,

F=4300

a=3.3m/s2

m=F/a

    =4300/3.3

    =1303.03kg

Approximately it is aqual to 1300kg

The solution is given in the image below

The wood before starting =12 feet

Left wood=6 feet

Wood used till now=12-6=6 feet

Picture frame built till now= 6/(3/4)

=8 pieces

Therefore, till now 8 pieces have been made.

Let the father's age be x and son's be y

10 years before-

Father age=x-10

sons age=y-10

Given,

x-10=10(y-10)

x-10=10y-100

Given present age of father=40

therefore,

x=40

40-10=10y-100

10y-100=30

10y=130

y=130/10

y=13

Therefore present age of son=13years