Correct option is B
Given:
Sum of two numbers = 10
Difference of their squares = 60
Concept Used:
Algebraic equations and solving them.
a² - b² = (a + b)(a - b)
Solution:
Let the two numbers be x and y.
x + y = 10 (Equation 1)
x² - y² = 60 (Equation 2)
x² - y² = (x + y)(x - y)
Substitute the given value: (x + y)(x - y) = 60
Substitute the value of (x + y) from Equation 1:
10(x - y) = 60
x - y = 6 (Equation 3)
Solve Equations 1 and 3 simultaneously:
x + y = 10
x - y = 6
Add the two equations: 2x = 16
x = 8
Substitute the value of x in Equation 1:
8 + y = 10
y = 2
Therefore, the two numbers are 8 and 2.
Alternate Solution:
From x+y=10, we can say x=10-y.
Substitute that into x²-y²=60.
(10-y)²-y²=60
100-20y+y²-y²=60
100-20y=60
40=20y
y=2
Substitute y=2 into x+y=10.
x+2=10
x=8.
The numbers are 8 and 2.