Ques:- A prime number N, in the range 10 to 50 remains unchanged when its digits are reversed. The square of such a number is
A. 1936
B. 1089
C. 484
D. 121
Ques:- If a 200 m long train crosses a platform of the same length as that of the train in 20 seconds, then the speed of the train is
A. 50 km/hr
B. 60 km/hr
C. 70 km/hr
D. 72 km/hr