# Bike Ride

Nirmala and Riki live in different villages.

Both villages are $9$ kilometres away from the nearest
market.

Nirmala rides her bike at $6$ kilometres per hour and Riki rides
his

at $4$ kilometres an hour.

They both want to arrive at the market at exactly noon.

What time should each of them start riding?

Well done to everyone who sent in solutions for this one. The
following people managed to have the correct leaving times for both
of the riders as well as explaining how they worked it out:**Chris**
(Ranelagh,Bracknell)**Thomas** and
**Ben** (Yarm Primary
School, Stockton on Tees)**Jason** (Priory Middle
School, Dunstable)**Rowena****Jesse and** **Sally** from Tattingstone School,
UK**Jonathon
(**Crofton Junior School, Kent) Excellent
presentation!

The answer was explained well by **Emily (**Tattingstone School)

"To work out this problem all I did was find out how long it would
take them to get there and subtracted it away from the 12:00
deadline.

For example, if it took Nirmala 1 hour to go 6 km, it would take
her 11/2 hours to get there because I had to add on the extra 3 km.
(I worked out that it would be 1/2 hour extra because 6 is one hour
so half of 6 is 3 and 3 would therefore be 1/2 an hour).

PHEW!

If she wanted to get there for noon she would have to
**leave at 10:30**.

I did the same to work out how long it would take for Riki to
get there. If it took him 1 hour to go 4 km it would take 2 hours
to go 8 km. He had 1 km to go and I found that it would take him an
extra 15 minutes to get there because if it takes 1/2 an hour (30
mins) to go another 1 km. So altogether it would take him 2 hours
and 15 mins to get there and he would therefore have to
**leave at 9:45**.

PHEW AGAIN!"

Most people did it the way described by Emily, but
**Daniel (**Anglo-Chinese
School, Singapore) did it differently. He took the distance to
Market and divided it by the distance travelled in one hour. The
answer gave the number hours it would take. So....

9 000 m divided by6 000 m = 1.5 hours

9 000m divided by 4 000 m = 2.25 hours