Ques:- Four of the following five are alike in a certain way and hence form a group. Which one of the following does not belong to that group?
A. 63
B. 64
C. 39
D. 48
E. 79
Ques:- Gold is 19 times as heavy as water and copper is 9 times. In what ratio should these metals be mixed so that the mixture may be 15 times as heavy as water?
A. 2 : 1
B. 3 : 2
C. 4 : 3
D. 5 : 4