Question

What value should come in place of the question-mark (?) in the following questions:

(64/25)?  × (125/512)?-1 =  5/8

A 3 Correct Answer Incorrect Answer
B 8 Correct Answer Incorrect Answer
C 4 Correct Answer Incorrect Answer
D 12 Correct Answer Incorrect Answer
E 2 Correct Answer Incorrect Answer

Solution

? = x 〖(8/5)〗^2x  × 〖(5/8)〗^(3x-3)=  5/8  ⇒ 〖(5/8)〗^(-2x)  × 〖(5/8)〗^(3x-3)=  5/8  ⇒ (5/8)^(-2x+3x-3) =  5/8 ⇒ (5/8)^(x-3) =  5/8 ⇒x-3=1 ⇒x=4 

Practice Next

Relevant for Exams:

×
×