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Ques:- A car travels a certain distance taking 7 hrs in forward journey, during the return journey increased speed 12km/hr takes the times 5 hrs.What is the distance travelled
A. 210 kms
B. 30 kms
C. 20 kms
D. none of these
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