Question

Say 1-50 words without letter "A" within 20 seconds?

Answer 1

yup, the numbers from one to hundred.. all the words from the number one to hundred. we cant find 'a'. :)
so, the 50 words are
one to fifty
and 100 are one to hundred all the numbers in word forms

Answer 2

if u know counting from 1-50 in English then you can do it in 15 sec.
because there is no 'a' in counting from 1-50. 

thanku..

have a nice day...