Problem: The difference between two numbers is five and the difference between their squares is 65. What is the larger number?
View all: BANGLADESH BANK OFFICER | WRITTEN QUESTION (MATH) SOLVE | 2015
Correct Answer: ans: Larger number is 9.
Explanation:
Let, the larger number be x
And the small one is y
According to the question
x – y = 5 …………….(i)
x$^{2}$- y$^{2}$ = 65 ……………..(ii)
Now, from the equation (ii), we have
x$^{2}$- y$^{2}$ = 65
=> (x +y) (x—y) = 65
=> (x +y) (x—y) = 65
=> (x + y) x 5 = 65
x + y = 13……….. (iii)
Adding equation (iii) & (i)
Now, we get
2x = 18
x = 9