Answer:
5.5%
Step-by-step explanation:
Given data
Simple interest = $137.50
Principal= $500
time = 5 years
We want to find the rate R
Simple interest= PRT/100
137.50 = 500*R*5/100
137.50=2500R/100
cross multiply
137.5*100= 2500R
13750= 2500R
divide both sides by 2500
R= 13750/2500
R=5.5%
Hence the rate is 5.5%
Answer:

Step-by-step explanation:
From figure,

In triangle 

![\Rightarrow (a+b)^2=(a-b)^2+(O' D)^2\\\Rightarrow a^2+b^2+2ab-a^2-b^2+2ab=(O' D)^2\\\Rightarrow 4ab=(O' D)^2\\\Rightarrow O'D=2\sqrt{ab} \\\Rightarrow O' D=2\sqrt{ab}=AB \quad \quad [\because O' DAB\;\; \text{is a rectangle.}]](https://tex.z-dn.net/?f=%5CRightarrow%20%28a%2Bb%29%5E2%3D%28a-b%29%5E2%2B%28O%27%20D%29%5E2%5C%5C%5CRightarrow%20a%5E2%2Bb%5E2%2B2ab-a%5E2-b%5E2%2B2ab%3D%28O%27%20D%29%5E2%5C%5C%5CRightarrow%204ab%3D%28O%27%20D%29%5E2%5C%5C%5CRightarrow%20O%27D%3D2%5Csqrt%7Bab%7D%20%5C%5C%5CRightarrow%20O%27%20D%3D2%5Csqrt%7Bab%7D%3DAB%20%5Cquad%20%5Cquad%20%5B%5Cbecause%20O%27%20DAB%5C%3B%5C%3B%20%5Ctext%7Bis%20a%20rectangle.%7D%5D)
Hence, 
Answer:
15 students
Step-by-step explanation:
No. of boys students = No. of all students - No. of girls
no. of boys =50-15 = 35 boys
the boys that will play the match are 2/7 of boys = (2/7)x35 = 10 boys
and the girls that will play the match are 5 girls
so, no of students chosen to play = 5+10=15 students
In general, 23 more than a number is written as

In our case, x is 'twice a number'; thus,

Finally, the whole expression is

<h2>The answer is 2n+23</h2>