If 2^(x + y) = 4^8, what is the value of y? (1) x^2 = 81 (2) x − y = 2 : Crackverbal Support

If 2^(x + y) = 4^8, what is the value of y? (1) x^2 = 81 (2) x − y = 2 Print

Modified on: Tue, 12 Oct, 2021 at 5:06 PM

Concept: The question tests on the application of exponents and equation in a DS format.

Solution:

2^x+y = (2²)⁸ = 2¹⁶

x +y = 16

St (1) x2= 81 and thus x = 9, - 9

Hence y = 7, 25

No unique value of y is obtained. Insufficient

St (2) x-y =2

Along with x + y =16 (given) a unique value of y = 7 can be obtained.

Thus Sufficient.

Hence option (b)

Did you find it helpful? Yes No

Help Desk Software by Freshdesk Support Desk