Solution:

A parachute

Solution:

Amelia --> vanilla-shake
Charlotte --> chocolate-shake
Evelyn --> strawberry-shake
Anna --> burger
Ella --> curd

Solution:

6

It takes two hours for one worker to paint one wall.
In six hours therefore one worker can paint 3 rooms, hence you need six painters to paint eighteen rooms

Solution:

6380

2*2-1 3*3-1 =>38
4*4-1 5*5-1 =>1524 and so on

Solution:

Step 1) Pour 1 liter of Water from gallon A to gallon C. Now 4 liter of Water is left in the gallon A and gallon C is full.

Step 2) Pour Water from gallon C to gallon B. Now as soon as gallon B is full , you know there is one liter of Water is in gallon C.

Solution:

Steps
1. Monica go from side A to B for approx 59 minutes
2. Lisa then move back to side A for 2 minutes to fool guard. Now guard will think she is coming to side A.
3. then she again move toward B :-)

Solution:

Of course, it is impossible. Into the second room should have gone the 2nd guest, because the 13th guest was waiting in room number 1

Solution:

Both would be the same distance from City owlna. (since they are at a same point)

Solution:

Nine (eight sons have same one sister ,so 8+1=9)

Solution:

Simply push the cork into the bottle and shake the marble out.