Question

second third and fourth terms of proportions are 18 10 and 20 respectively then find its first term​

Answer 1

Answer:

The fourth term is 36.

Step-by-step explanation:

Given : First, Second and third terms of a proportion are respectively 20, 18 and 40.

To find : The fourth term ?

Solution :

If the four terms are in proportion a:b:: c:da:b::c:d then \frac{a}{b}=\frac{c}{d}

b

a

=

d

c

First, Second and third terms of a proportion are respectively 20, 18 and 40.

i.e. a=20, b=18 and c=40

Substitute,

\frac{20}{18}=\frac{40}{d}

18

20

=

d

40

d=\frac{40\times 18}{20}d=

20

40×18

d=36d=36

Therefore, the fourth term is 36.

#Learn more

In a proportion , the 1st, 2nd and 4th terms are 51,68,108 respectively. Find the 3rd term.

Answer 2

Answer:

The first term is 9

Step-by-step explanation:

x : 18 :: 10 : 20

=> x : 18 = 10 : 20

=> x/18 = 10/20

=> x = 18 × 1/2 = 9