SOME QUESTION OF ARITHMETIC

1> The difference of 40% discount on Rs. 500 and successive discounts of 36% and 4% on Rs. 500 is 
A) Rs. 2              B)  Rs. 0         C) Rs. 18           D)  Rs. 7.20

2> 14 persons can sink a tubewell in 12 days. How many extra persons are required to sink the tubewell in 8 days ?
A)  9 persons          B)6 persons        C) 3 persons           D)7 persons

3> After ringing together 5 bells begin to ring at intervals of 9 sec, 6 sec, 4 secs, 10 secs and 8 secs respectively. How many times the bells will ring together in one hour starting from first time ringing together ?
A) 11 times    B)9 times   C) 8 times   D) 12 times

4> The H.C.F. of the three numbers 1.7, 0.51 and 0.153 is
A) 0.17     B)0.017      C)0.0017       D)1.7