Question

Can you help me solving these problems?

Answer 1

@satellite73

Answer 2

@Nurali @cwrw238

Answer 3

#11) There are 9 coins and 3 denominations total.
Pick one coin at a time and the different amounts (in cents) are: 1, 5, 10
Pick two coins at a time and the different amounts (in cents) are: 1+1, 1+5, 1+10, 5+5, 5+10, 10+10
....and so on and so forth until all 9 coins are chosen for a maximum amount of 3*(1+5+10) = 48 cents.

Answer 4

thanks @aum Can you help me with the rest? Please!!!!!

Answer 5

#12) AED is a right triangle because AD^2 = AE^2 + ED^2
Angle AED = 90 degrees.
Drop a vertical line from E to AD and let this line make angle theta with AE.
AEcos(theta) = EDcos(90-theta)
3cos(theta) = 4sin(theta)
tan(theta) = 3/4
Find theta.
Then the height of the rectangle = AEcos(theta) = 3cos(theta)

Area of rectangle = 5 * 3 * cos(theta)

Answer 6

thanks so
15*cos(theta) is the answer for #12? @aum

Answer 7

theta is an angle we introduced and so we have to get rid of it in the final answer.

Answer 8

okie got #12

Answer 9

Area = 5 * 3 * 4/5 = 12

Answer 10

Wow. Didn't think of that. Please help me with the last one. I don't really understand the question

Answer 11

#13)

Answer 12

Where the does 12 go on triangle 2?

Answer 13

One of the sides of the second triangle is 12. But of the three sides which one is 12?

If you assign 12 to the longest side, then the scale factor will be minimum and so the perimeter will be the minimum.

Answer 14

If you assign 12 to the shortest side, then the scale factor will be maximum and so the perimeter will be the maximum:

Answer 15

Remember, the sides of similar triangles are proportional. If you know one side (length = 12) and the proportionality constant you can find the other two sides.

Answer 16

okie got it. Thank you so much for your help

Answer 17

You are welcome.

Answer 18

Perhaps a slightly easier way to do problem #11:
The lowest amount she can make is 1 cent.
The highest amount she can make is 48 cents.
Go through all the numbers in between and see if she make that combination with 3 pennies, 3 nickels and 3 dimes.
2 cents? - yes; 3 cents - yes?; 4 cents? - no; 5,6,7,8 cents = yes; 9 cents - no,
.....

In short, she can make all combinations from1 to 48 except those ending in a 4 or a 9.
Can't make: 4, 9, 14, 19, 24, 29, 34, 39, 44.