Question

what is a counterexample for the conjecture?
conjecture: all balls are spheres
a) a basketball
b) a football
c) a circle
d) a baseball

Answer 1

which of the four choices is NOT a sphere?

Answer 2

c

Answer 3

nope, think again

what shape is basketball? what shape is a football? what shape is a baseball?

Answer 4

try google images if you are unsure

Answer 5

a baseball

Answer 6

nope, try again...

here is a picture of a baseball: https://www.bing.com/images/search?q=baseball&view=detailv2&&id=BEB2CBE2C319E1671DE145612130643561CD730C&selectedIndex=1&ccid=qA%2b5t6zj&simid=608056048580494219&thid=JN.HfwX1A%2bYgKNXCcpmuIOcOw&ajaxhist=0

here is a picture of a football: https://www.bing.com/images/search?q=football&view=detailv2&&id=14F055156B47EA92692DD4F73F3BC0EF8C59C29B&selectedIndex=2&ccid=JJCTHpJQ&simid=607997314896496844&thid=JN.ZKUoVP4svd%2b6A7ndIsnhyA&ajaxhist=0

here is a picture of a basketball: https://www.bing.com/images/search?q=basketball&view=detailv2&&id=165F83777E94B99DA9A03456EF85F54E39A6FDC3&selectedIndex=0&ccid=KEaana%2bg&simid=608021590055256860&thid=JN.ogY6obzN5%2bS%2fu9ph4WtrQQ&ajaxhist=0

which one is NOT a sphere?

Answer 7

a football

Answer 8

yup, so that's our answer

Answer 9

b