Question
Find the fourth proportion to the following:
$3,5$ and $15$
$3,5$ and $15$
✓
Answer
Let $x$ be the fourth proportion to $3,5$ and $15$
$3: 5:: 15: x $
$\Rightarrow 3 \times x=5 \times 15$
$\Rightarrow x=\frac{5 \times 15}{3}$
$\Rightarrow x=25$
The fourth proportion is $25 .$
$3: 5:: 15: x $
$\Rightarrow 3 \times x=5 \times 15$
$\Rightarrow x=\frac{5 \times 15}{3}$
$\Rightarrow x=25$
The fourth proportion is $25 .$
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
The radii of the internal and external surface of a metallic spherical. It is melted and recast intoa solid right circular cone of height $32\ cm.$ Find the diameter of the base of the cone.
→A heap of wheat is in the form of a cone of diameter $16.8\ m$ and height $3.5\ m.$ Find its volume.How much cloth is required to just cover the heap?
→The average score of boys in an examination of a school is $71$ and of girls is $73.$ The averages score of school in that examination is $71.8.$ Find the ratio of the number of boys between number of girls appeared in the examination.
→$A, B$ and $C$ are collinear points such that $A B=\frac{1}{2} A C$. If the coordinates of $A, B$ and $C$ are $(-4,-4)$ $(-2, b)$ anf $(a, 2)$, Find the values of $a$ and $b$.
→In a cyclic quadrilateral ABCD , AB || CD and ∠ B = 65° , find the remaining angles.
In figures, find the length CF.
The sum of the ages of Vivek and his younger brother Amit is $47$ years. The product of their ages in years is $550$. Find their ages.
→A dice is thrown once. What is the probability of getting a number: less than or equal to 2?
Solve the following inequation, write down the solution set and represent it on the real number line:
$-2+10 x \leq 13 x+10<24+10 x, x \in Z$
→$-2+10 x \leq 13 x+10<24+10 x, x \in Z$
Prove the following identity:
$
\sec ^2 A \cdot \operatorname{cosec}{ }^2 A=\tan ^2 A+\cot ^2 A+2
$
→$
\sec ^2 A \cdot \operatorname{cosec}{ }^2 A=\tan ^2 A+\cot ^2 A+2
$