X
It is now three years since I first asked for support, and I would like to sincerely thank everyone who has helped me. BrainBashers doesn't show adverts, and I continue to depend on the ongoing support from everyone who enjoys the site.
support BrainBashers
?
Puzzle 65
Which of the shapes is identical to the first one?
The final of the BrainBashers triathlon was a close run thing.
The whole tournament was decided on the last two sections, cycling and the road race.
Alex didn't win either section. The person who won the cycling came third in the road race. Alex beat Charlie in cycling, but was beaten by Charlie in the road race. Charlie was last in neither section. Drew won the road race, but was beaten by Billie in the cycling.
Can you work out who came where in each section?
Hint
In the road race, where could Charlie have finished?
Answer
Cycling : Billie > Alex > Charlie > Drew
Road race : Drew > Charlie > Billie > Alex
Road Race
In the road race, where could Charlie have finished?
By (4), he wasn't last. By (5), he wasn't first.
By (2), if Charlie was third, then he would have won the cycling, but by (3) Alex beat Charlie in the cycling, so Charlie can't have won the cycling.
So Charlie must have finished in second place.
By (5), Drew was first.
By (1), Alex didn't win the cycling, so by (2) he didn't come third in the road race. Therefore, Alex came last.
Leaving Billie in third place.
Road race : Drew > Charlie > Billie > Alex
Cycling
By (2), Billie won.
By (4), Charlie wasn't last.
By (3), Alex beat Charlie. So Alex finished in second place, with Charlie in third place.
Leaving Drew in last place.
Cycling : Billie > Alex > Charlie > Drew
??
Puzzle 68
Farmer Stone is quite an eccentric dairy farmer.
He originally had a total of 54 gallons of milk in three churns, and he wanted to make sure each churn contained 18 gallons of milk.
In order to do this, he did the following:
First, he poured 1/4 of the first churn into the second churn. He then poured 1/2 of the second churn into the third churn. Finally, he poured 1/3 of the third churn into the first churn.
How many gallons did each churn contain before Farmer Stone started pouring?
Hint
Try working backwards with each churn containing 18 gallons.
Answer
12, 33, and 9 gallons respectively for churns 1, 2, and 3.
Reasoning
Working backwards, at the end after Pour 3, the churns (C1, C2, C3) contained:
C1 C2 C3
————————————
18 18 18 after Pour 3
Pour3 was 1/3 of C3 into C1, the remaining 2/3 has to be the 18 gallons left in C3 after the pour, which means that 1/3 is 9 gallons. So 9 gallons was poured from C3 into C1. Before Pour3, C1 must have contained 9 gallons, and C3 contained 27 gallons.
C1 C2 C3
————————————
9 18 27 after Pour 2
18 18 18 after Pour 3
Pour2 was 1/2 of C2 into C3, the remaining 1/2 has to be the 18 gallons left in C2 after the pour, which means that 1/2 is 18 gallons. So 18 gallons was poured from C2 into C3. Before Pour2, C2 must have contained 36 gallons, and C3 contained 9 gallons.
C1 C2 C3
————————————
9 36 9 after Pour 1
9 18 27 after Pour 2
18 18 18 after Pour 3
Pour1 was 1/4 of C1 into C2, the remaining 3/4 has to be the 9 gallons left in C1 after the pour, which means that 1/4 is 3 gallons. So 3 gallons was poured from C1 into C2. Before Pour2, C1 must have contained 12 gallons, and C2 contained 33 gallons.
C1 C2 C3
————————————
12 33 9 at the start
9 36 9 after Pour 1
9 18 27 after Pour 2
18 18 18 after Pour 3
Note: BrainBashers has a Dark Mode option. For BrainBashers, I'd recommend not using your browser's built-in dark mode, or any dark mode extensions (sometimes you can add an exception for a specific website).
It is now three years since I first asked for support, and I would like to sincerely thank everyone who has helped me. BrainBashers doesn't show adverts, and I continue to depend on the ongoing support from everyone who enjoys the site.
