There are 4! = 24 poosible permutations of the four letters. Let the letters be A, B, C and D. Two permutations will have only letter A in the correct envelope, two more permutations will have only letter B in the correct envelope, two more will have only letter C in the correct envelope and two more will have only letter D in the correct envelope. Therefore 8 out of the 24 possible permutations will have only one letter with the correct address. The required probability is 8/24 = 1/3.
130 because your other angle be is 50 which completes the triangle. Angle f 40 Angle C 90 Angle B 50. 180 - 50 = 130
Answer:
Eli's age = 42 years
Step-by-step explanation:
Let x be Eli's age and y be Cecil's age
So,
According to the statement given
x+y=60 eqn 1
Eli's age 6 years ago = x-6
Cecil's age 6 years ago = y-6
So according to the given statement
x-6 = 3(y-6)
x-6 = 3y - 18
x-3y = -18+6
x-3y= -12 eqn 2
Subtracting eqn 2 from eqn 1
x+y - (x-3y) = 60 - (-12)
x+y-x+3y = 60+12
4y = 72
y = 18
Cecil's age = 18 years
Putting y = 18 in eqn 1
x+18=60
x = 60-18
x = 42
Eli's age = 42 years ..
The correct answer is A so it’s true
Answer:
D 3500
Step-by-step explanation:
This question is asking for the sum of all the terms in an arithmetic series.
So using the formula : Sn = n/2 (a+l) , where Sn is the sum of n terms, a is first term, and l is last term, we try to find Sn, with n being 25, a being 20, and an which is a25 or the twenty fifth term being 260, also being the last term.
Hence we can produce the formula for Sn which is Sn=25/2 (20+260)
Sn=25/2 (280)
=3500
