Answer:
x = 12
Step-by-step explanation:
Equation: 0.52(x) + 0.72(4) = 0.57(x + 4)
0.52(x) + 0.72(4) = 0.57(x + 4) 
Multiply
0.52x + 2.88 = 0.57x + 2.28 Subtract 0.52x from both sides
2.88 = 0.05x + 2.28 Subtract 2.28 from both sides
0.6 = 0.05x Divide all sides by 0.05
x = 12
-Chetan K
212
/ \
2 106
/ \
2 53
2800
/ \
2 1400
/ \
2 700
/ \
2 350
/ \
2 175
/ \
5 35
/ \
5 7
/ \
7 1
900
/ \
2 450
/ \
2 225
/ \
3 75
/ \
3 25
/ \
5 5
/ \
5 1
This might help if you need it again
Answer:
35 ways
Step-by-step explanation:
Alex has 9 friends and wants to invite 5 friends. Since Alex requires two of his friends who are twins to come together to his birthday party, since the two of them form a group, the number of ways we can select the two of them to form a group of two is ²C₂ = 1 way.
Since we have removed two out of the nine friends, we are left with 7 friends. Also, two friends are already selected, so we are left with space for 3 friends. So, the number of ways we can select a group of 3 friends out of 7 is ⁷C₃ = 7 × 6 × 5/3! = 35 ways.
So, the total number ways we can select 5 friend out of 9 to party come to the birthday include two friends is ²C₂ × ⁷C₃ = 1 × 35 = 35 ways
