快猫短视频

#250 Are we nearly there yet?

set by Howard Williams

鈥淗ow much further?鈥� asks my son Jack, from the back seat of the car. It鈥檚 a relief to have a variation, as all I鈥檝e heard from him in the past hour is 鈥渁re we nearly there yet?鈥�. If I鈥檓 not to go crackers, I need to give him something to occupy his mind.

So in answer to his question, I say, 鈥淛ack, an hour and a half ago we were a three-digit number of miles from our destination, with the middle digit being a zero. Three-quarters of an hour ago we had a two-digit number of miles still to travel, with its first digit being the same as the last digit of the three-digit distance and its second being the same as the first digit of the three-digit distance. We now still have a two-digit number of miles to travel, but its digits are the reverse of the previous two-digit number. As we are travelling at a constant speed, you should be able to calculate how many minutes it will take for us to arrive.鈥�

Silence reigned for at least 10 glorious minutes. Can you work out the answer?

Solution next week

#249 Espresso geometry

Solution

Three more pots will be needed.

This is easy to see if you rotate the smaller triangle so that it is upside down. The larger triangle is four times the size of the smaller one.