Posted by Dan on September 17, 2002 at 01:44:16:
In Reply to: Word Problem posted by Suzi on September 16, 2002 at 23:05:47:
Here is how you should Figure it
You travel for a total of 6 hrs for a total of 70 miles.
there are 2 parts to the trip
Parts Time Traveled Average Speed
1 2hrs(given) x
2 4hrs(6hrs-2hrs) 2 times x or 2x
so you plug these numbers into your a formula
*=times(multiply)
2*x + 4*2x = 70
2x + 8x = 70
10x = 70
x = 7
So on the first leg her average speed was 7 mph
and on the second led her average speed was 14mph
Parts Time Traveled Average Speed
1 2hrs(given) 7
2 4hrs(6hrs-2hrs) 14
That is how you solve it.