Problema Solution
A bottle and a cup exactly balance a coffeepot. The bottle balances a cup and saucer. Three saucers can be used to balance two coffeepots. How many cups will it take to balance a bottle?
Answer provided by our tutors
Let b, c be the weights of bottle, cup.
Weight of coffeepot =b+c
Three saucer balance 2 coffeecups, so 3 saucers weigh 2(b+c)
1 saucer weighs 2/3 (b+c)
The bottle balances a cup and a saucer
b = c + 2/3 (b+c)
3b = 3c + 2b +2c
b = 5c.
5 cups needed to balance a bottle.