Management Aptitude Test Sep 2013 Paper

(a) Distance covered by wheel in one revolution
= Circumference of wheel = 2 πr = 2π$\frac{\mathit{d}}{2}$
= 2 x $\frac{22}{7}\times \frac{1.4}{2}$ = 4.4 m
Now, 66 km/h in m/s = 66 x $\frac{5}{18}=\frac{55}{3}$ m/s
Now, wheel covers $\frac{55}{3}$ m in 1 s
∴ Distance covered by wheel in per minute = $\frac{55}{3}$ x 60 = 55 x 20 = 1100 m
Let number of rotation taken by wheel to cover 1100 m = n
Then, n x 4.4 = 1100
n = $\frac{1100}{4.4}=\frac{11000}{44}$
= 250 rotation per minute