#76 Four hippos
The rangers at the Savannah Wilderness Experience are on a mission to weigh the four adult hippos in the park. Their scales can bear a weight of up to 4 tonnes, but are unreliable with anything below 2 tonnes, and all the hippos weigh less than that, so the rangers have had the smart idea of weighing the hippos in pairs.
The first five weighings are: 2.23, 2.35, 2.48, 2.72 and 2.85 tonnes.
The rangers now guide the two heaviest hippos onto the scales, but as the weighing is about to take place, the lightest hippo sneaks on as well and the scales break.
How much does the lightest hippo weigh?
Answer next week
#75 Seventh time lucky?
Solution
The code is 4321. Septa has four correct digits in six goes. No digit appears in a column more than twice, so she has either got three of the digits correct twice or two digits correct twice and two once. The digits that appear twice are: 7 in the first column; 3 in the second column; 2 in the third column; 8 in the fourth column. The only pair of these that doesn鈥檛 coincide is x 3 2 x. One of the digits 4 8 8 2 is correct. Since 2 can鈥檛 be repeated, it must be 4, and from 1191, the last digit must be 1.
Quick quiz #68
1 Diversity in what feature of Galapagos island finches was considered by Charles Darwin to be prime evidence for his theory of evolution by natural selection?
2 Psilocybin is a mind-altering drug most notoriously found where?
3 What is the signature feature of an ekpyrotic universe?
4 Weak electrical forces between atoms and molecules that aren鈥檛 considered to be chemical bonds are often named after which Dutch theoretical physicist?
5 What is the difference between autosomal-dominant and autosomal-recessive genetic diseases?
Answers on page 54
Answers
1 Their beaks
2 In 鈥渕agic鈥� mushrooms
3 It is cyclical 鈥� expanding, contracting and being constantly reborn
4 Johannes Diderik van der Waals
5 In autosomal-dominant conditions, you need only inherit a mutated gene from one parent; in autosomal-recessive conditions you need to inherit a mutated gene from both parents