A man drive his car to the office at 20miles/hr.
After reaching office, he realize that its a new year holiday so he went back home at a speed of 30miles/hr.
Discounting the time spent in the stoppage what was his average speed of his journey ?  Choose the correct choice from the following answers
A) 21	B) 20	C) 25	D) 24	E) 29
24   24miles/hr (not 25miles/hr which might be guessed by many)   24 : distance traveled   T1 : time of going to office   T2 : time of returning back   Y : Average Speed   24 = 20 * T1   T1 = 24/20   24 = 30 * T2   T2 = 24/30   224 = Y(T2 + T1)   224 = Y(24/20 + 24/30)   224 = Y(324/60 + 224/60)   224 = Y(524/60)   Y = 12024/524   =&gt; Y = 24
<result>D</result>
A man drive his car to the office at 20miles/hr.
After reaching office, he realize that its a new year holiday so he went back home at a speed of 30miles/hr.
Discounting the time spent in the stoppage what was his average speed of his journey ?