Question Detail

Find the fourth proportion to 2,3,6

Answer: Option C

Explanation:

2:3 :: 6:x

=> 2/3 = 6/x
=> x = 18/2
=> x = 9

1. The sum of three numbers is 98. If the ratio of the first to the second is 2:3 and that of the second to the third is 5:8, then the second number is

Answer: Option D

Explanation:

\begin{aligned}
a:b = 2:3 \\
b:c = 5:8 = (5*\frac{3}{5} : 8*\frac{3}{5}) \\
= 3:\frac{24}{5} \\
a:b:c = 2:3:\frac{24}{5} \\
= 10:15:24 \\
b = 98*\frac{15}{49} \\
= 30
\end{aligned}

2. If A:B:C = 2:3:4, then find

\begin{aligned}
\frac{A}{B}:\frac{B}{C}:\frac{C}{A}

\end{aligned}

5:9:24
6:9:24
7:9:24
8:9:24

Answer: Option D

Explanation:

Let A = 2x, B = 3x, C = 4x, then,
\begin{aligned}
\frac{A}{B} = \frac{2x}{3x} = \frac{2}{3} \\
\frac{B}{C} = \frac{3x}{4x} = \frac{3}{4} \\
\frac{C}{A} = \frac{4x}{2x} = \frac{2}{1} \\

=> \frac{A}{B}:\frac{B}{C}:\frac{C}{A} \\
= \frac{2}{3}:\frac{3}{4}:\frac{2}{1} \\
= 8:9:24

\end{aligned}

3. If 2 : 9 :: x : 18, then find the value of x

Answer: Option C

Explanation:

Treat 2:9 as 2/9 and x:18 as x/18, treat :: as =

So we get 2/9 = x/18
=> 9x = 36
=> x = 4

4. There are two numbers and their ratio is 3 : 9. If we substract 9 from both numbers then their ratio becomes 12 : 13, what is value is smaller number ?

Answer: Option D

Explanation:

From question, lets assume that two numbers are 3x and 5x.

\begin{aligned}
\text{then, }\frac{3x - 9}{ 5x - 9} = \frac{12}{23}\\
=> \text{23(3x - 9) = 12(5x - 9)}\\
=> 9x = 99 \\
=> x = 11
\end{aligned}
So numbers are 3(11) = 33, 5(11) = 55.
Smaller number is 33.

5. Two numbers are respectively 20% and 50% more than a third number. The ratio of the two numbers is

Answer: Option C

Explanation:

Let the third number be x.
First Number (120/100)*x = 6x/5
Second Number (150/100)*x = 3x/2

Ratio = 6x/5:3x/2
=> 4:5

Question Detail

Find the fourth proportion to 2,3,6

1. The sum of three numbers is 98. If the ratio of the first to the second is 2:3 and that of the second to the third is 5:8, then the second number is

2. If A:B:C = 2:3:4, then find \begin{aligned} \frac{A}{B}:\frac{B}{C}:\frac{C}{A} \end{aligned}

3. If 2 : 9 :: x : 18, then find the value of x

4. There are two numbers and their ratio is 3 : 9. If we substract 9 from both numbers then their ratio becomes 12 : 13, what is value is smaller number ?

5. Two numbers are respectively 20% and 50% more than a third number. The ratio of the two numbers is

2. If A:B:C = 2:3:4, then find

\begin{aligned}
\frac{A}{B}:\frac{B}{C}:\frac{C}{A}

\end{aligned}