tomsun

hint: you use the mid-point formula. 

see this link for the formula: https://www.thoughtco.com/geometry-midpoint-formula-2312239

I will give the answer later

see https://web2.0calc.com/questions/help_28639 for answers.

what do you mean by 4i? 41 or you actually mean 4i?

This guest was always saying these things when M got help... 

Wonder if he ever got tired of posting. 

we know that 10 3-dollars will worth 30 dollars, so items that cost 3 dollars have to be less than ten. 

We also know that 10 30-cents will worth 3 dollars, so the number of cents has to come in 10s since the final cost is 30 which is a whole number.

There will be a lot of cents, so I will just say that there are 20 30-cents, which will cost 6 dollars. If I add 6 2-dollars, then I will get 12 dollars. 12 +6=18. 30-18=12. and 12/3=4. 

4 items cost $3

6 items cost $2

20 items cost 30 cents

A convex octagon has interior angles that add to (8 - 2)(180) = 1080 degrees

If there is one right angle, the remaining angles must average (1080-90) / 7 ≈ 141.4 degrees

If there are two right angles, the remaining angles must average (1080 - 180) / 6 = 150 degrees

If there are three right angles, the remaining angles must average (1080 - 270) / 5 = 162 degrees

If there are four right angles, the remaining angles must average (1080 - 360) / 4 = 180 degrees, but this isn't possible while remaining convex.

So the largest possible number of right angles is three.

(Thank you for helping me with the other math problems I posted earlier... )

I think the answer is... not b, or a... c likely.

Anyone?

just learn all the topics.

*you can practice math problems in Aops online.*

At 9:00, the hands form a right-angle (90°) or you can think of it as 270° if you look at the angle between the minute and the hour hand.

MINUTE HAND RATE:

Now the minute hand moves 1/60 of the way around the circle each minute. 1/60 of 360° is 6°

The minute hand moves 6° per minute.

HOUR HAND RATE:

The hour hand moves 1/12 of the way each hour. Dividing by 60, that means the hour hand moves 1/720 of the way around the circle each minute. 1/720 * 360° = ½°

The hour hand moves ½° per minute.

Thus the minute hand is getting 6° closer, but the hour hand is moving away at a rate of ½° per minute. That's a net of 5½° per minute that they are getting closer together.

You want to figure the minutes until the 270° angle is down to 28°.

Set up an equation:

270 - 5.5t = 28

270 - 28 = 5.5t

242 = 5.5t

t = 242/5.5

t = 484/11

t = 44

Answer: 

In 44 minutes (at 9:44).