Answer:11
Step-by-step explanation:
Boys : girls=7:1
Sum of ratio=7+1=8
Let them number of girls be y
Then they number of boys=y+66
Total number of pupils=y+y+66
Total number of pupils=2y+66
Number of girls=(girls ratio)/(sum of ratio) x (total number of pupils)
y=1/8 x (2y+66)
Cross multiply
y x 8=2y + 66
8y=2y + 66
Collect like terms
8y-2y=66
6y=66
Divide both sides by 6
6y/6=66/6
y=11
The number of girls is 11
Answer: 98.90
Step-by-step explanation:
115*.2=23
115-23=92
0.075*92=6.9
6.90+92=$98.90
Parallel would be anything with the slope of 4x and perpendicular would be anything with the slope of 1/4
<h3>To ProvE :- </h3>
- 1 + 3 + 5 + ..... + (2n - 1) = n²
<u>Method</u><u> </u><u>:</u><u>-</u>
If P(n) is a statement such that ,
- P(n) is true for n = 1
- P(n) is true for n = k + 1 , when it's true for n = k ( k is a natural number ) , then the statement is true for all natural numbers .
Step 1 : <u>Put </u><u>n </u><u>=</u><u> </u><u>1</u><u> </u><u>:</u><u>-</u><u> </u>
Step 2 : <u>Assume </u><u>that </u><u>P(</u><u>n)</u><u> </u><u>is </u><u>true </u><u>for </u><u>n </u><u>=</u><u> </u><u>k </u><u>:</u><u>-</u>

- Add (2k +1) to both sides .
- RHS is in the form of ( a + b)² = a²+b²+2ab .
- Adding and subtracting 1 to LHS .
- P(n) is true for n = k + 1 .
Hence by the principal of Mathematical Induction we can say that P(n) is true for all natural numbers 'n' .
<em>*</em><em>*</em><em>Edits</em><em> are</em><em> welcomed</em><em>*</em><em>*</em>