Question

p, q and r are three sums of money such that q is the simple interest on p and r is the simple interest on q for the same time and same rate. Which of the following is correct?

• A. $q^2=p\times r$
• B. $q=p\times r$
• C. $p\times q\times r=1$
  
• D. $p^2=q\times r$

Answer 1

The correct option is A $q^2=p\times r$

Let the time be T,
Let the rate of interest be R
$q=\frac{p\times T\times R}{100}$.....(1)
$r=\frac{q\times T\times R}{100}$......(2)
Dividing (1) and (2)
$\frac{q}{r}=\frac{p}{q}$
$\therefore q^2=p\times r$