Help with my math homework! Simple Critical Thinking math! Also for people who just want some brain teasers!?

Question

Okay this is my math extra credit and please no stupid answers like I don't want to do your homework or I will report you.
Okay 10 points to the best answer lets begin!
1)You have a bucket that holds 4 gallons or water and a second bucket the holds 7 gallon of water. The buckets have no markings. How can you go to the well and bring back exactly 5 gallons of water?
2)Okay this one involces a picture I will describe it best I can. It is a picture of 3 dots evenly placed out and a line under it and 3 foot steps under the line. Suppose you are a detective and found these tracks on some damp ground. Do you have any ideas how they were made?
3) Why are 1980 pennies worth almost 20$? (I don't think the answer is obvious as it look and maybe involves what the value of pennies in 1980 was.)
4) Another picture but very simple. 3 blank boxes plus another 3 blank boxes equal 3 blank boxes. Place the digits 1 through 9 in the nine squares to form a correct addition. Is there other ways todoit

Answer 1

1) Name the buckets as 4G (4 gallon) and 7G (7 gallon)
i) Fill 4G from well.
ii) Pour water from 4G to 7G.
iii) Again, fill 4G from well.
iv) Pour water from 4G to 7G till 7G is full. Thus 1 gallon water remains in 4G.
v) Empty the 7G into well.
vi) Pour the 1 gallon water (now present in 4G) from 4G to 7G.
vii) Fill 4G from well.
viii) Pour 4G to 7G which now contains 1 gallon of water.
Thus you have 5 gallons of water in 7G bucket.

2) The person who walked the road is lame and walks with the help of a crutch. Further a bike followed / chased him / her (the possibility that the person followed / chased the bike is ruled out since he / she is lame).

3) 1980 pennies = $19.8 which is approximately $20.

4) 124 + 365 = 489; 142 + 356 = 498; 421 + 563 = 984; 412 + 536 = 948; etc.

Answer 2

1) fill the 4 gal bucket and put it in the 7 gal bucket
0, 4
fill the 4 gall bucket
4, 4
put all that will go in the 7 gal bucket
1, 7
empty the 7 gal bucket
1, 0
pour the 1 gal from the 4 gal bucket into the 7 gal bucket
0, 1
fill the 4 gal bucket
4, 1 (stop here and bring both buckets back)
or pour it into the 7 gal bucket
0, 5 (5 gal in the 7gal bucket - probably the best way to carry without spilling it)

2) you could have a man with a bike and a peg leg. The bike would make a straight line, one foot would make footprints and the other foot would make dots

3) 1980 pennies are worth $19.80 (because each penny is worth one cent). It's a trick to make you think of the year 1980 instead of the amount 1980.

4) this may be problem involving matches. Can you move the matchsticks around so that you have three boxes?

Answer 3

1) first you bring 4 gallons,then you fill the 4 gallon bucket and pour it in the 7-gallon bucket,refill the 4-gallon and complete from it the 7-gallon bucket, what is lift in the 4-gallon is 1-gallon,empty the 7-gallons in the well , then oour the 1-gallon from the 4-gallon into the 7-gallon.refill the 4-gallon bucket and return back with 1-0gallon in the 7-gallon bucket,and 4-gallon bucket full.
2)they were made by a one foot man and his stick.
3)may be they were able to buy somethig that worth $20 now.

Answer 4

Can answer only the first one - not sure if its the best way to do it though.

Fill the 7 Lts bucket, then transfer the water to the 4 Lts one. So now you have 3 Lts in the 7 Lt buc, and 4 in the other.

Empty the 4 lts bucket, and transfer the water from the 7 lts buc into it. Now you have the 7 lt buc empty, and 3 lts in the 4 lt buc.

Fill the 7 lt buc again and transfer water from the & lt buc to the 4 lt buc. Because the 4 lt buc already has 3 lts in it, you now have 6 Lts in the 7 lt buc, and 4 lts in the 4 lt buc. Empty the 4 Lt bucket now. So 6 lts in the 7 lt buc and the 4 lt buc is empty.

Transfer water from the 7 lt bus to the 4 lt buc. Which leaves you with 2 lts in the 7 lt buc and 4 lts in the 4 lt buc.

Empty the 4 lts buc and transfer the water from the 7 lt buc into in. so you have 2 lts in the 4 lt buc and the 7 lt buc is empty.

Fill the 7 lt buc and transfer water to the 4 lts buc. because it already has 2 lts, it will only take 2 lts and you will have 5 lts in the 7 lt buc.

Too long I know, must be an easier way!