
Thank you.the top question did I get correct.thanks.the second question is a bit confused.thanks.
Thank you.the top question did I get correct.thanks.the second question is a bit confused.thanks.
Question 10:
<——————180km———————–>
X |<—————–|——————————->| Y
Lorry(9:30) 11:00 Car(9:30)
Speed of car = u
Speed of lorry = u-30
11:00-9:30 = (3/2)h Using distance = speed x time,
(3/2)u + 3/2 (u-30) = 180 <——– x 2 on both sides
3u + 3u – 90 = 360
6u = 450 => u = 75
Hence speed of car is 75km/h
PS: Please click ” Accept Answer” if the answer is correct.
Question 9:
Your working is partially correct. You start getting wrong when you add speed to distance. They cannot be added together.
P |——————————-|—————-|———————>| Q
H<—- 12 –>A<——- u———>
A = 80km/h after (3/4) h, Distance travelled by A = 80 x (3/4) = 60
H = 64km/h after (3/4) h, Distance travelled by H = 64 x (3/4) = 48
Distance between them after 45 mins = 60 – 48 = 12
Let u be the distance of A’s remaining journey to Q
Time taken by A to complete remaining journey = u/80
H increases speed to 86km/h for the remaining journey
Remaining journey of H = 12 + u
Time taken by H to complete remaining journey = (12+u)/86
They arrived at the same time at Q,
u/80 = (12+u)/86
86u = 80u + 960
6u = 960 => u = 160
Hence the distance between town P and Q = 60+160 or 48+12+160 = 220km
PS: Please click ” Accept Answer” if the answer is correct.
Hi Prettyhomework,
If the answer is incorrect, please provide the answer key so that corrections can be made.