A basic question from ML aggarwal book of class 10th chapter 7 ratio and proportion, exercise 7.2
In this ques we have been given three numbers and we are asked to find 4th number that can make all the four numbers in proportion
Question 1, exercise 7.2
Solution:
(i) 10: 35 = x: 42
We can write it as
35 × x = 10 × 42
So we get
x = (10 × 42)/ 35
x = 2 × 6
x = 12
(ii) 3: x = 24: 2
We can write it as
x × 24 = 3 × 2
So we get
x = (3 × 2)/ 24
x = ¼
(iii) 2.5: 1.5 = x: 3
We can write it as
1.5 × x = 2.5 × 3
So we get
x = (2.5 × 3)/ 1.5
x = 5.0
(iv) x: 50 :: 3: 2
We can write it as
x × 2 = 50 × 3
So we get
x = (50 × 3)/ 2
x = 75