Answer:
4
Step-by-step explanation:
He should add 4 black blocks because there are a total of 4 other blocks, and in order to have a probability of 50%, the number of black blocks needs to be equal to the total number of the other colored blocks.
Answer:
<em>First.</em> Let us prove that the sum of three consecutive integers is divisible by 3.
Three consecutive integers can be written as k, k+1, k+2. Then, if we denote their sum as n:
n = k+(k+1)+(k+2) = 3k+3 = 3(k+1).
So, n can be written as 3 times another integer, thus n is divisible by 3.
<em>Second. </em>Let us prove that any number divisible by 3 can be written as the sum of three consecutive integers.
Assume that n is divisible by 3. The above proof suggest that we write it as
n=3(k+1)=3k+3=k + k + k +1+2 = k + (k+1) + (k+2).
As k, k+1, k+2 are three consecutive integers, we have completed our goal.
Step-by-step explanation:
Answer:
2 - 
Step-by-step explanation:
Using the addition formula for tangent
tan(A - B) =
and the exact values
tan45° = 1 , tan60° =
, then
tan15° = tan(60 - 45)°
tan(60 - 45)°
= 
=
Rationalise the denominator by multiplying numerator/ denominator by the conjugate of the denominator.
The conjugate of 1 +
is 1 -
=
← expand numerator/denominator using FOIL
= 
= 
=
+ 
= 2 - 
Answer:
A. 19,70,91
Step-by-step explanation:
Interior angle =180
19+70+91=180
Answer:
6
Step-by-step explanation:
5% of 120 were late
=
× 120
= 0.05 × 120
= 6