Answer:
66
Step-by-step explanation:
Use the formula for the mean of a set of numbers:
sum of the numbers
average = --------------------------------
count of numbers
Here we know that the average mark was 68, so we can write:
75 + 62 + 84 + 53 + x
average = 68 = ----------------------------------
5
or 274 + x
68 = -------------------
5
Solving for x, we multiply both sides by 5: 340 = 274 + x.
Subtracting 274 from both sides effectively isolates x:
340 = 274 + x
- 274 -274
------------------------
66 = x
The fifth student's mark was 66.
X = 10
The triangles are similar by SAS, so we can set up a proportion of their sides.
9/(33-9) = 12/(3x+2)
9/24 = 12/3x+2
Reduce
3/8 = 12/3x+2
Cross multiply
3(3x+2) = 12*8
Distribute and multiply
9x + 6 = 96
Subtract 6
9x = 90
Divide by 9
x = 10
Check:
9/24 = 12/3x+2
9/24 = 12/3*10 + 2
9/24 = 12/30 + 2
9/24 = 12/32
3/8 = 3/8 :)
Step-by-step explanation:
Square= bh
Square= 2×2=
half-circle = 1/2Pi*r×r
half-circle 2 = 1/2Pi*r×r
We would put 1/2 for the half-circle because its half of a circle. And we square it because where finding area. The middle is square, and the two up top is half a circle. Hope that helps :D
You would have 20 quarters to make 5 dollars
