The left hand side of the equation is a difference of two squares and may be factored out as follows, (x - 4)(x + 4) > 0 They may be individually taken as, x - 4 > 0 ; x > 4 x + 4 > 0 ; x < -4 Thus, the answer to this item is letter A.
We know that: time=distance/speed if the tortoise speed is x m/min, then since 0.5 m/hr=1/120 m/min 18/x=23+18/(x+1/120) solving for x we get: x=0.08 m/min speed of hare is: (0.08+1/120)=0.088 m/min
