Two numbers are named Number A and Number B. The sum of Number A, Its square, and Its cube is 399. The sum of Number B, Its square, and its cube is 819. what would be the square of the number obtained by adding Number A and Number B?
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. 256.
According to the question;
A + A2 + A3 = 399
B + B2 + B3 = 819
We need to check for the result by the hit and trial method.
The number 399 is nearer to cube 343. So, we can consider A = 7.
The number 819 is nearer to cube 729. So, we can consider B = 9.
So, we will check whether it is true or not.
7 + 72 + 73 = 7 + 49 + 343 = 399
9 + 92 + 93 = 9 + 81 + 729 = 819
So, (A + B)2 = (7 + 9)2 = (16)2 = 256