Surds And Indices Q2

2.Given that 100.48 = x, 100.70 = y and xz = y2, then the value of z is close to:

     A.   1.45

     B.   1.88

     C.   2.9

     D.   3.7

Answer:

Option : C 

Given, x^z = y²

⇒ 10^(0.48z) = 10^{(2 x 0.70)} = 10^1.40

⇒ 0.48z = 1.40

⇒	z =	140	=	35	= 2.9 (approx.)
		48		12