Vehicles Meeting D7C617
1. **Problem statement:**
Two vehicles start from towns A and B, 360 km apart. The minibus leaves A at 8:15 am traveling at 90 km/h. The matatu leaves B 2 \frac{1}{3} hours later (which is 2.333 hours) traveling at 110 km/h towards A. We need to find:
- The time they meet (12-hour clock).
- The distance from A where they meet.
- The distance from the motorist's home to A, given he leaves at 10:30 am at 100 km/h and arrives at B at the same time as the minibus.
2. **Step 1: Define variables and times**
- Distance between A and B: $d = 360$ km
- Minibus speed: $v_m = 90$ km/h
- Matatu speed: $v_t = 110$ km/h
- Minibus start time: 8:15 am
- Matatu start time: $8:15 + 2.333$ hours = $8:15 + 2$ hours 20 minutes = 10:35 am
3. **Step 2: Let $t$ be the time in hours after 8:15 am when they meet.**
- Distance minibus travels: $90t$
- Matatu starts after 2.333 hours, so it travels for $(t - 2.333)$ hours (only if $t > 2.333$)
- Distance matatu travels: $110(t - 2.333)$
4. **Step 3: Since they meet, sum of distances equals total distance:**
$$90t + 110(t - 2.333) = 360$$
5. **Step 4: Solve for $t$:**
$$90t + 110t - 110 \times 2.333 = 360$$
$$200t - 256.67 = 360$$
$$200t = 360 + 256.67 = 616.67$$
$$t = \frac{616.67}{200} = 3.0833 \text{ hours}$$
6. **Step 5: Convert $t$ to time:**
- $3.0833$ hours = 3 hours + 0.0833 hours
- $0.0833 \times 60 = 5$ minutes
- Meeting time = 8:15 am + 3 hours 5 minutes = 11:20 am
7. **Step 6: Distance from A where they meet:**
$$\text{Distance} = 90 \times 3.0833 = 277.5 \text{ km}$$
8. **Step 7: Motorist leaves at 10:30 am and arrives at B at the same time as minibus (11:20 am).**
- Travel time for motorist: $11:20 - 10:30 = 50$ minutes = $\frac{50}{60} = 0.8333$ hours
- Motorist speed: 100 km/h
- Distance motorist travels: $100 \times 0.8333 = 83.33$ km
9. **Step 8: Since motorist travels from home to B, and distance B to A is 360 km, the distance from home to A is:**
$$360 - 83.33 = 276.67 \text{ km}$$
**Final answers:**
- The vehicles meet at **11:20 am**.
- They meet **277.5 km** from A.
- The motorist's home is **276.67 km** from A.