Marcus rode his bicycle to the park at 14 mph. He rode from the park at 21 mph. If the total trip took 3 1/2 hours, how far was it to the park?
2006-12-15 13:06:53 · 3 answers · asked by kmckenz754 1 in Science & Mathematics ➔ Geography
Total Distance: 29.4 miles
Trip 1
r= 14 mph t=? D=?
Trip 2
r=21 mph t=3.5 HS - t D=?
r.t = d
14t=21 (3.5 - t)
t=2.1 14mph for 2.1 hours = 29.4 miles
Trip 2 21mph for 1.4 hours = 29.4 miles
2006-12-15 14:31:55 · answer #1 · answered by vlake_phoenix 2 · 1⤊ 0⤋
Use the formula:
time = distance / rate
t1 = d/14
t2 = d/21
t = t1 + t2 = 7/2 = d/14 + d/21
Clear the denominators by multiplying by 42
7*21 = 3d + 2d
147 = 5d
d = 147/5 miles = 29.4 miles
2006-12-15 21:32:57 · answer #2 · answered by Northstar 7 · 0⤊ 0⤋
The first answer is correct for the one way distance , but
you need to double it to get the total distance, so 58.8miles.
My mistake. I thought the question was to answer the total
distance, and it is asking for the one way distance.
2006-12-15 16:59:32 · answer #3 · answered by les 4 · 0⤊ 0⤋