Question

3: 78 :: 5:?
(A) 120
(B) 125
(C) 135
(D) 115​

Answer 1

3 : 78 : : 5 :

$\frac{3}{78} = \frac{5}{x} \\ \\ 3x = 78 \times 5 \\ 3x = 390 \\ x = \frac{390}{3} \\ \\ x = 130$

130 is the answer but it's not there in options..

Answer 2

Answer:

130

Step-by-step explanation:

Given:

3:78::5:?

To find:

Missing number

Solution:

3:78::5:?

Let x be the missing number of the proportion

We know that

When two ratios are equal then we say that the ratios are in proportion.

a:b::c:d

a/b=c/d

Using the property

\frac{3}{78}=\frac{5}{x}

78

3

=

x

5

Using cross multiplication

3x=5\times 783x=5×78

x=\frac{5\times 78}{3}=130x=

3

5×78

=130