Answer:
10 years ago
Step-by-step explanation:
Let x be the number of years ago
x years ago,
Sonu's grandmother was 80 - x
Sonu was 20 - x
x years ago,
the grandmother was 7 times as old as Sonu
80 - x = 7(20 - x)
80 - x = 140 - 7x
6x = 60
x = 10
Answer:
Step-by-step explanation:
i dont know
Answer:
Gray family's sprinkler was used for 40 hours.
Thompson family's sprinkler was used for 35 hours.
Step-by-step explanation:
The Gray family and the Thompson family each used their sprinklers last summer.
Let x= amount of time in hours that the Gray family's sprinkler was used.
Let y = amount of time in hours that the Thompson family's sprinkler was used.
The water output rate for the Gray family's sprinkler was 40 L per hour. The water output rate for the Thompson family's sprinkler was 20 L per hour. This means that the combined number of hours that both family's used their sprinklers is 40x + 20y
The families used their sprinklers for a combined total of 75 hours, resulting in a total water output of 2300 L .
This means
x + y = 75
40x + 20y = 2300 - - - - - - - -1
Substituting x = 75 -y into equation 1,
40 ( 75 - y ) + 20y = 2300
3000 - 40y + 20y = 2300
-40y + 20y = 2300 - 3000
-20y = -700
y = 700/20 = 35 hours
x = 75 - y
x = 75 -35 = 40 hours
To find the number of miles driven on one gallon, divide 420 by 20. that would be 21. multiply 21 by 65 to find the number of miles you can drive with 65 gallons.
Answer:
go step by step with the process to solve
Step-by-step explanation:
