a2zinterviews

6.	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

Solution

xz = y² <=> (10 0.48 )z <=> (100.70)2 = (10 0.48z) = (10(2×0.70)) = 101.40 0.48z = 1.40 z= 140/48 = 35/12 = 2.9(approx.).

7.	The value of (256)5/4 is
	A.  984
	B.  512
	C.  1014
	D.  1024

Solution

(256)5/4 =(44)5/4 =4(4x5/4) = 45 = 1024.

8.	If 3(x-y)= 27 and 3(x+y)=243, then x is equal to
	A.  0
	B.  2
	C.  4
	D.  6

Solution

3(x - y) = 27 = 33 x - y = 3. ......(1) 3(x+y) = 243 = 35 x + y = 5. .......(2) On solving equations 1 and 2, we get = x=4.

9.	If ax =b, by= c and cz= a, then the value of xyz is
	A.  0
	B.  1
	C.  2
	D.  abc

Solution

a1 = cz =(by)y =(byz) =(ax)yz Therefore, xyz= 1

10.	49× 49× 49× 49 = ?
	A.  4
	B.  7
	C.  8
	D.  16

Solution

49× 49× 49× 49 = (72 ×72 ×72 ×72 = 7(2+2++2+2) = 78 So, the correct answer is 8.