Let selling price = SP and cost price = CP
He makes 20 % on selling price means = >
(sp-cp) / sp = 20 % = 20/100 = 0.2
(sp - cp) / sp = 0.2
1 - cp/sp = 0.2
1 - 0.2 = cp/sp
0.8 = cp/sp
Reversing 1 / 0.8 = sp/cp = 1.25
We need to find profit on cost price means =
=(sp-cp)/ cp
= sp/cp - 1 = 1.25 - 1 = 0.25
Means 25 % profit on cost price : Answer
Hope that will help :)
Difference in doughnuts = 50 - 40 = 10
Difference in money = 15 + 5 = 20
20 ÷ 10 = $2
Each doughnut costs $2
<em>Check:</em>
40 x 2 + 5 = $85
50 x 2 -15 = $85
Ravi has $85 at first.
Each doughnut costs $2
Answer:
4 liters of 60% solution; 2 liters of 30% solution
Step-by-step explanation:
I like to use a simple, but effective, tool for most mixture problems. It is a kind of "X" diagram as in the attachment.
The ratios of solution concentrations are 3:6:5, so I've used those numbers in the diagram. The constituent solutions are on the left; the desired mixture is in the middle, and the numbers on the other legs of the X are the differences along the diagonals: 6 - 5 = 1; 5 - 3 = 2. This tells you the ratio of 60% solution to 30% solution is 2 : 1.
These ratio units (2, 1) add to 3. We want 6 liters of mixture, so we need to multiply these ratio units by 2 liters to get the amounts of constituents needed. The result is 4 liters of 60% solution and 2 liters of 30% solution.
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If you're writing equations, it often works well to let the variable represent the quantity of the greatest contributor—the 60% solution. Let the volume of that (in liters) be represented by v. Then the total volume of iodine in the mixture is ...
... 0.60·v + 0.30·(6 -v) = 0.50·6
... 0.30v = 0.20·6 . . . . subtract 0.30·6, collect terms
... v = 6·(0.20/0.30) = 4 . . . . divide by the coefficient of v
4 liters of 60% solution are needed. The other 2 liters are 30% solution.
Answer:
8cm²
Step by step explanation:
A= ½×4cm×4cm
A= ½×16cm²
A= 8cm²