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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
Ques:- A train of length 150 metres takes 40.5 seconds to cross a tunnel of length 300 metres. What is the speed of the train in km/hr?
A. 13.33
B. 26.67
C. 39.16
D. 40
Ques:- Two trains are coming from opposite directions with speeds of 75 km/hr and 100 km/hr on two parallel tracks. At some moment the distance between them is 100 km. After T hours, distance between them is again 100 km. T is equal to
A. 1 hr
B. $$1{1} / {7}$$
C. $$1{1} / {2}$$
D. 2 hrs