Trains Boats and Streams Practice Test 1 with solutions

Let the length of both trains = x m
Speed of the two trains = 46 km/hr and 36 km/hr
Faster train passes the slower train in 36 seconds
So, time = $\left(\frac{\mathit{a}+\mathit{b}}{\mathit{u}-\mathit{v}}\right)$
36 = $\left(\frac{\mathit{x}+\mathit{x}}{\frac{46\times 5}{18}-\frac{36\times 5}{18}}\right)$
36 = $\left(\frac{2\mathit{x}}{\frac{115}{9}-10}\right)$
36 = $\left(\frac{2\mathit{x}}{115-90}\times 9\right)$
36 × 25 = 18x
x = $\frac{900}{18}$ = 50 m