Re: pre-algebra question- help!!!
MARIE said:
I have been stuck on these two questions for hours. Can someone please help me?
The volume of a rectangle box is 20 cubic inches. If the top is 2 inches by 2.5 inches, what is the height?
How can you be stuck for so long? You either have the formula or you don't.
Volume of Rectangular Box = Length * Width * Height
Substitute Known Values
20 in^3 = 2 in * 2.5 in * Height
Solve for the missing piece.
Height = (20 in^3)/(2 in * 2.5 in) = (20/(2*2.5)) in = 4 in
Recommendation: Don't do that again. Go do something else until you have the right tools. Stressing is never beneficial.
Jeb has 15 coins. They are all quarters and dimes. He has a total of $2.10. How many dimes does he have?
Name things. Did you cover this in class at all? Wait - you posted in pre-algebra. Well, okay, let's think about it.
$2.10 made up of quarters and dimes.
The most quarters is 2.10/.25 = 8.4 -- So at most 8 quarters
The most dimes is 2.10/0.10 = 21 -- So, at most 21 dimes.
Thinking about the quarters...With a total of $2.10, there must be some EVEN number of quarters. You tell me why that is. Think about multiples and that last pennies digit.
Wait, it's pretty obvious that 8 quarters makes $2.00. Add one dime and we get $2.10. Too bad it says 15 coins. We almost had it!
Now what do you suppose we do?
