I dont know the answer sorry am a biginner
Answer:

Step-by-step explanation:
Given: 
To find: 
Solution:
From the image, 
Put 


Therefore,

The correct answer is B :)
There will be 4 rows and 3 in each row. one more cube will be placed at the bottom.
hope it helps!
Answer:
7/20
Step-by-step explanation:
You have: 3/5 - 1/4
When you have different denominator:
1) Multiply in cross. The numerator of the first fraction is multiplied by the denominator of the second, and the denominator of the first by the numerator of the second. Both multiplications are subtracted.
3/5 - 1/4 = [(3*4) - (5*1 )] / ...
2) The denominators of the two fractions are multiplied.
3/5 - 1/4 = [(3*4) - (5*1 )]/(5*4
)
3) Resolve operations
= (12-5)/20
= 7/20