Question

An athlete completes one round of a circular track
of radius 10m in 40sec.The distance covered by
him in 2min 20sec is (a)70m (b)140m (c)110m
(d)220m

Answer 1

(d). 220m.
circumfrence of circle=2πr
r=10.i.e 2*3.14*10
=2*31.4 in 40 sec.
dist. covered into 1 sec=2*31.4/40=1.57.
dist covered into 120+20=140 sec=1.57*140=219.8
approx 220 m

Answer 2

r=10 m
circumference=2*22/7*r
                    =62.85 m
t=40 s
total time=2*60+20
             =140 s
distance ran=140*62.85/40
                  =219.975 m
                  =220 m
so,option(D)