She worked as a carpenter for 12 hours and as a blacksmith for 18 hours.
Assuming you mean she earned $20 as a carpenter and $25 as a blacksmith per hour, with a total of 30 hours for $690,
let c represent carpenter hours and b for blacksmith hours.
20c + 25b = 690
c + b = 30
Subtract b from each side so that c = 30 - b
Plug this value into the first equation
20(30 - b) + 25b = 690
600 - 20b + 25b = 690
600 + 5b = 690
5b = 90
b = 18
To find c, plug this value of b into the other equation
c + 18 = 30
c = 12
Answer:
0:42
Step-by-step explanation:
Answer:
number of dimes 11 to 14
Step-by-step explanation:
given data
coin = 19
worth no less = $1.30
Nolan nickles = 5
solution
we convert 5 cent to dollars, it will be
5÷100 = $0.05
and
dime is worth 10 cents
so it will be 10 ÷ 100 = $0.1
so we consider here x as the number when nickels.
and we consider y as the number of dimes.
so here we can say
x + y ≤ 19 ..........................1
as here no less than $1.30 combined.
so
0.05 x + 0.1 y ≥ 1.3 ......................2
and
when Nolan has 5 nickels
put x = 5 in eq 1
5 + y ≤ 19
y ≤ 19 - 5
y ≤ 14
and
now we put x = 5 in eq 2
0.05 × 5 + 0.1y ≥ 1.3
0.25 + 0.1y ≥ 1.3
0.1y ≥ 1.3 - 0.25
0.1y ≥ 1.05
y ≥ 10.5
so all possible values for the number of dimes 11 to 14
9 millimeters= 0.9 centimeters
