Practicing Success

Target Exam

CUET

Subject

General Test

Chapter

Numerical Ability

Topic

Time, Speed and Distance

Question:

The distance covered by a train in $(5 y-1)$ hours is $\left(125 y^3-1\right)$ km. The speed of the train is:

Options:

$\left(5 y^3-1\right)$ km/h

$\left(25 y^2-5 y+1\right)$ km/h

$(5y+1)$ km/h

$\left(25 y^2+5 y+1\right)$ km/h

Correct Answer:

$\left(25 y^2+5 y+1\right)$ km/h

Explanation:

Distance = Speed  × Time

Speed =\(\frac{125y^3 - 1 }{(5y - 1)}\)

By using formula :-

a^3 - b^3 = (a-b) ( a^2 + b^2 + ab)

Speed = ( 25y^2 + 5y + 1 ) km/h