Question

ratio 5 : 7: 8.
8. Divide
9. Divide + 440 in the ratio
10. The first three terms of a proportion are 3, 5 and 21 respectively. Find its fourth term.
1 1
5 6
fin of copper and zine in all​

Answer 1

Answer:

Step-by-step explanation:

The first three terms of a proportion are 3, 5 and 21 respectively. Find its fourth term.

Given, the first three terms of a proportion are 3,5 and 21 respectively.

Let the fourth number be x  

So, Numbers proportion are 3,5,21,x

According to proportionality,

Product of means = Product of extremes

3:5::21:x

 3/5 ​  =   21 /x

​Cross multiply,

3×x=21×5

3x=105

x=35

Therefore, The required fourth number is 35