Pergunta de entrevista da empresa Jane Street

What is 19% of 19?

Respostas da entrevista

Sigiloso

13 de fev. de 2012

3.61

Sigiloso

30 de mar. de 2012

19 x .2 = 3.8, therefore, 3.8 - 1/100 of 19 (.19) = 3.61

Sigiloso

5 de jun. de 2012

19*19 = 20*18 + 1 = 361, so 3.61 Alternatively: 19*19 = 10*28 + 81 = 361, so again 3.61 See Ars Calcula for the relevant mental math tricks: http://arscalcula.com/