Question

State which of the following are in proportions:

(i) $6:18::5:15$

Answer 1

Checking for proportionality:

If four numbers $x,y,z,w$ are in proportion i.e., $x:y::z:w$, then the product of extremes is equal to the product of means i.e. $xw=yz$.

In the given expression, $x=6,y=18,z=5,w=15$.

Now, $xw=6\times 15=90$ and $yz=18\times 5=90$.

Therefore, it can be concluded that $xw=yz$.

Final Answer: Hence, the given expression represents a proportion.