Pair of Linear Equations in Two Variables
CBSE 2026 Board Exam Set 2 (Code 30/1/2)
CBSE_BOARD_PYQ_2026_30_1_2
Grade 10
Question:
[Section D]
A motor boat whose speed is $18$ km/h in still water takes $1$ hour more to go $24$ km upstream than to return downstream. Find speed of stream.
OR
Two water taps fill a tank in $9\dfrac{3}{8}$ hours. Larger tap takes $10$ hours less than smaller one. Find individual times.
Step-by-Step Solution
Key Concept: Upstream/downstream equation.
[Main Question Solution]
$24/(18-x) - 24/(18+x) = 1 \Rightarrow x = 6$ km/h. [5.0 Marks]
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[OR Choice Question Solution]
$1/x + 1/(x-10) = 8/75 \Rightarrow x = 25$ hours. [5.0 Marks]
Correct Answer: Main: 6 km/h | OR: Larger = 15 hrs, Smaller = 25 hrs
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