Jenny had driven for 2 h at a constant speed when road repairs forced her to reduce her speed by 10 mp/h for the remaining 1 h of her 152 mile trip. Find her original speed.
a.471/3mi/h
B.
54 mi/h
C.
56 mi/h
D.
none of these
2006-11-14 02:46:45 · 9 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
Rate * Time = Distance
2x = Rate (x) * Time (2) for first two hours
x-10 = Rate (x-10) * Time (1) for third hour
2x + (x-10) = 152
3x-10 = 152
3x =162
x = 54
The correct answer is B. 54mph
2006-11-14 03:09:54 · answer #1 · answered by Forward Kindness 3 · 0⤊ 0⤋
y mph x 2 + (y-10) mph x 1 =152
2y + y - 10 = 152
3 y = 142
y = 47 1/3 mph
answer is a.
2006-11-14 10:55:21 · answer #2 · answered by ignoramus 7 · 0⤊ 0⤋
B. 54 mph
becasue 54mph x 2= 108...
108...+44mph= 152miles
2006-11-14 10:51:30 · answer #3 · answered by Anonymous · 0⤊ 0⤋
b; 2x+y=152, x-y=10; 3x=162; x=54
2006-11-14 10:54:28 · answer #4 · answered by ewd_03101 2 · 0⤊ 0⤋
let the original speed be x
distance travelled=2x
it is decreased by 10
i.e, x-10mph
2x+x-10=152
3x=162
x=54
Ans:B
2006-11-14 10:57:16 · answer #5 · answered by . 3 · 0⤊ 0⤋
D.
71mph
2006-11-14 10:56:07 · answer #6 · answered by openpsychy 6 · 0⤊ 0⤋
Answer is B 54mph
2006-11-14 10:58:58 · answer #7 · answered by Mikem 3 · 0⤊ 0⤋
b
2006-11-14 10:51:27 · answer #8 · answered by Vladimir S 2 · 0⤊ 0⤋
B
2006-11-14 10:52:26 · answer #9 · answered by Anonymous · 0⤊ 0⤋