Races and Games Practice Test 1 with solutions

Total number of rounds made by Ram in $\frac{15}{4}$ hrs = $5\times \frac{15}{4}$ = $\frac{75}{4}$
Total number of rounds made by Karan in $\frac{15}{4}$ hrs = $\frac{36}{7}\times \frac{15}{4}$ = $\frac{135}{7}$
Total number of rounds made by Mohan in $\frac{15}{4}$ hrs = $\frac{16}{3}\times \frac{15}{4}$ = 20
H.C.F. of $\frac{75}{4},\frac{135}{7}$ and 2 = $\frac{5}{28}$
Hence, greatest length, the race course can have $\frac{5}{28}$ km.