Lcm Combo Packs
1. Problem 116: Find when all three stoves need refilling simultaneously.
We use the Least Common Multiple (LCM) of the refill times 18, 24, and 30 minutes.
2. Calculate prime factorizations:
- 18 = $2 \times 3^2$
- 24 = $2^3 \times 3$
- 30 = $2 \times 3 \times 5$
3. LCM takes the highest powers of each prime:
- For 2: $2^3$
- For 3: $3^2$
- For 5: $5$
4. Calculate LCM:
$$LCM = 2^3 \times 3^2 \times 5 = 8 \times 9 \times 5 = 360$$
Answer: 360 minutes (option a).
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5. Problem 117: Number of complete combo packs with 2 samosas, 3 jalebis, and 4 idlis.
Given quantities: 180 samosas, 150 jalebis, 120 idlis.
6. Calculate how many packs each ingredient can make:
- Samosas: $\frac{180}{2} = 90$
- Jalebis: $\frac{150}{3} = 50$
- Idlis: $\frac{120}{4} = 30$
7. The maximum number of complete packs is the minimum of these: 30.
Answer: 30 packs (option a).
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8. Problem 118: When will all three restock together?
Restock days: 12, 15, 20.
9. Find LCM of 12, 15, and 20.
Prime factorizations:
- 12 = $2^2 \times 3$
- 15 = $3 \times 5$
- 20 = $2^2 \times 5$
10. LCM takes highest powers:
- 2: $2^2$
- 3: $3$
- 5: $5$
11. Calculate LCM:
$$LCM = 2^2 \times 3 \times 5 = 4 \times 3 \times 5 = 60$$
Answer: 60 days (option b).
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12. Problem 119: Ravi doubles samosas to 360, Meera has 150 jalebis, Arjun has 120 idlis.
13. Calculate max identical boxes:
- Samosas: $\frac{360}{2} = 180$
- Jalebis: $\frac{150}{3} = 50$
- Idlis: $\frac{120}{4} = 30$
14. Minimum is 30, so max boxes = 30.
Answer: 30 (option a).
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15. Problem 120: Each combo pack has 3 samosas and 3 jalebis.
Available: 180 samosas, 150 jalebis.
16. Calculate max packs:
- Samosas: $\frac{180}{3} = 60$
- Jalebis: $\frac{150}{3} = 50$
17. Minimum is 50, so max packs = 50.
Answer: 50 (option c).