Answer:
D
Step-by-step explanation:
this is a "strategic" guess
Answer:
Tank which is capable of holding 1 can fill each one of the tanks an exact number of time.
Step-by-step explanation:
Three tanks are capable of holding 
To find which tank can be used to fill each one of them an exact number of time, find 
Therefore,
So, tank which is capable of holding 1 can fill each one of the tanks an exact number of time.
Answer:
B, it's the only plausible one. A is wrong because the value would be above 180°
Answer:
Pretend that x and y represents the 2 numbers that we need to find.
According to the information, we know that:
x + y = 21
6x = y
Replace y in the first equation with 6x (because they are equal to each other according to the second equation):
x + y = 21
x + 6x = 21
7x = 21
x = 21/7 = 3
Now have two ways to find y, both will give us the same result:
3 + y = 21 ⇔ y = 21 - 3 = 18
6 · 3 = y ⇔ y = 18
So the numbers that we need to find are 3 and 18.
