Question: 12. At Station X, the number of children was $\frac{3}{5}$ the number of adults on the train. At Station Y, $\frac{2}{9}$ of the adults and some children alighted from the train. The number of children became $\frac{3}{7}$ the number of adults. At Station Z, 358 children and 98 adults boarded the train and there was an equal number of adults and children.
(a) How many passengers were there on the train in the end?
Ans: a) ____________________ [4m]
(b) How many children alighted at Station Y?
Ans: b) ____________________ [1m]
1. **State the problem:**
We have a train with adults and children at Station X, Y, and Z with given ratios and changes. We want to find:
(a) The total number of passengers at the end.
(b) The number of children who alighted at Station Y.
2. **Define variables:**
Let $A$ = number of adults at Station X.
Let $C$ = number of children at Station X.
3. **From Station X:**
Given $C = \frac{3}{5}A$.
4. **At Station Y:**
- $\frac{2}{9}$ of adults alight, so adults remaining = $A - \frac{2}{9}A = \frac{7}{9}A$.
- Let $x$ = number of children alighting at Station Y.
- Children remaining = $C - x$.
- New ratio: $\frac{C - x}{\frac{7}{9}A} = \frac{3}{7}$.
5. **Express $x$ in terms of $A$:**
$$\frac{C - x}{\frac{7}{9}A} = \frac{3}{7} \implies C - x = \frac{3}{7} \times \frac{7}{9} A = \frac{3}{9} A = \frac{1}{3} A$$
Substitute $C = \frac{3}{5} A$:
$$\frac{3}{5} A - x = \frac{1}{3} A \implies x = \frac{3}{5} A - \frac{1}{3} A = \frac{9}{15} A - \frac{5}{15} A = \frac{4}{15} A$$
6. **At Station Z:**
- 358 children and 98 adults board.
- Adults after Station Z: $\frac{7}{9} A + 98$.
- Children after Station Z: $C - x + 358 = \frac{1}{3} A + 358$ (from step 5).
- Given adults = children after Station Z:
$$\frac{7}{9} A + 98 = \frac{1}{3} A + 358$$
7. **Solve for $A$:**
$$\frac{7}{9} A - \frac{1}{3} A = 358 - 98$$
$$\frac{7}{9} A - \frac{3}{9} A = 260$$
$$\frac{4}{9} A = 260 \implies A = 260 \times \frac{9}{4} = 585$$
8. **Find $C$ and $x$:**
$$C = \frac{3}{5} \times 585 = 351$$
$$x = \frac{4}{15} \times 585 = 156$$
9. **Find total passengers at the end:**
Adults after Station Z:
$$\frac{7}{9} \times 585 + 98 = 455 + 98 = 553$$
Children after Station Z:
$$\frac{1}{3} \times 585 + 358 = 195 + 358 = 553$$
Total passengers:
$$553 + 553 = 1106$$
**Final answers:**
(a) Total passengers at the end = **1106**
(b) Children alighted at Station Y = **156**