difference between two numbers is 30twice the greater number is less then 7times the smaller number by 5 find the numbers
Answers
Given :-
- Difference between two numbers is 30
- Twice the greater number is less then 7 times the smaller number by 5
To find :-
- The greater and the smaller number
Solution :-
Let the greater number be x
Let the smaller number be y
As per the first condition,
- Difference between two numbers is 30
Representing it mathematically, we get our first equation,
x - y = 30 ----> 1
As per the second condition,
- Twice the greater number is less then 7 times the smaller number by 5,
Let's represent it mathematically to get our second equation,
2x = 7y + 5
2x - 7y = 5 ---->2
Now, we will use elimination method to solve equations 1 and 2, simultaneously. But before that let's equate one of the terms of both the equations.
Multiply equation 1 by 2,
x - y = 30
2 × x - 2 × y = 2 × 30
2x - 2y = 60 ---->3
Solve equations 2 and 3 simultaneously by subtracting equation 3 from 2,
...2x - 2y = 60 -----> 3
- (2x - 7y = 5)-------> 2
--------------------------
5y = 55
y =
y = 11
•°• Smaller number, y = 11
Substitute y = 11 in equation 1,
x - y = 30
x - 11 = 30
x = 30 + 11
x = 41
•°• Greater number, x = 41
•°• The numbers are : 41 and 11
For first case :-
- Difference between two numbers is 30
Numbers = 41 & 11
Difference = 30
Let's see if the condition is satisfied,
41 - 11 = 30
30 = 30
LHS = RHS
For second case :-
- Twice the greater number is less then 7 times the smaller number by 5
Greater number = 41
Twice the greater number = 2 (41) = 82
Smaller number = 11
Seven times the smaller number = 7 (11) = 77
Let's check whether the condition is satisfied,
82 = 77 + 5
82 - 77 = 5
5 = 5
LHS = RHS
Hence our answer is right.