Answer:
a = -10
Step-by-step explanation:
-0.4a + 3 = 7
subtract 3 from each side
-0.4a + 3-3 = 7-3
-.4a = 4
Divide each side by -.4
-.4a/ -.4 = 4/-.4
a = - 10
If he puts 300 sunfish into the pond, he will put 225 perch in the pond.
<h3>What is a ratio?</h3>
A ratio is the comparison of one thing to another. Generally, ratios compares value.
They store the children pond keeping a ratio of 4 sunfish to 3 perch. Therefore, the ratio of sunfish to perch will be as follows
If he 300 sunfish into the pond , the number of perch that will be in the pond can be calculated as follows:
cross multiply
4x = 900
x = 900 / 4
x = 225
learn more on ratios here: brainly.com/question/89456?referrer=searchResults
20% of 60 is 12
60/300 = 20%
The friend is incorrect because that is 20% of 300 not 60
The difference between the 26 mile trip and 38 mile trip is 12 miles.
The difference in the price is $3.00 ($65.50 - $62.50)
So those 12 miles cost $3.00 $3.00÷12 = $.25 per mile
We can use either given trip to solve. I will use the 38 mile trip.
The difference between 38 miles and 54 miles is 16 miles. At $.25 a mile those 16 miles will add $4.00 to the price. ($.25 x 16 = $4.00)
Since the 38 mile trip costs $65.50 we add $4.00 and get $69.50 for a 54 mile trip.
Answer:
24.83 hours
Step-by-step explanation:
Given that :
Let time taken by pumps be :
Pump A = 60 hours
Pump B = 80 hours
Pump C = 90 hours
Recall :
Rate = 1 / time taken
The rates of the pumps are :
Pump A rate = 1 / 60
Pump B rate = 1/80
Pump C rate = 1/90
Combined rate : 1/60 + 1/80 + 1/90
Combined rate = (12 + 9 + 8) / 720 = 29/720
Combined rate = 29/720
The time taken together will be :
1 / combined rate = 1/(29/720) = 720 / 29 = 24.827 hours
