overyourhead

Brain Teaser Answers...

Well done Luca. Well done anon.

1. 45 minutes. In 24 hours, the cold tap could fill 80 baths, the hot tap could fill 96 baths and the plug could drain 144 baths. Therefore, in 24 hours, we have 80 + 96 - 144 baths full = 120 baths. Therefore each bath would take 45 minutes to fill.

time (min) x rate (gal/min) = cap (gal)
18 ct = 15 ht = 10 pl = bath
time x (ct + ht - pl) = bath
time = bath / (ct + ht - pl)
time = bath / (bath/18 + bath/15 - bath/10)
time = 1 / ( (15 + 18 - 27) / 270) = 1 / (6/270) = 270/6 = 45 mins

2. Pineapple = 83p, coconut = 57p, melon = 62p.

m + c = 119p
m + p = 145p
c + p = 140p

m - c = 5p
2m = 124p
m = 62p
c = 57
p = 83p