Question

John started Tom live $15km$ apart. On a day, john started to ride his bicycle towards Tom's house. A little lateral Tom stated to ride his bicyle towards john's house. When they met, john had ridden for twice the length of time as Tom and at four-sevenths of Tom's speed. How many $km$ has Tom ridden when they met?

• A. $4$
• B. $5.5$
• C. $7.5$
• D. $8$
• E. $Noneofthese$

Answer 1

The correct option is C $7.5$

Tom's speed $=15km/h$,

John's speed $=10km/h$

So, in 15 minutes, Tom takes a lead of $\frac{15-10}{60}\times 15=\frac{5}{4}km$

John has to cover this $\frac{5}{4}km$

With speed of 10 km/h, he will cover this distance in $\frac{5}{4}\times \frac{60}{10}$ = $\frac{15}{2}$ $=7.5$ mins