CL-USER> (generate-captcha)
"what is 4 plus 6?"
"10"
CL-USER> (generate-captcha)
"what is 6 minus 6?"
"0"
CL-USER> (generate-captcha)
"what is 2 times 5?"
"10"
CL-USER> (generate-captcha)
"what is 4 minus 3?"
"1"
CL-USER> (generate-captcha)
"what is 3 minus 8?"
"-5"
CL-USER> (generate-captcha)
"what is 1 times 2?"
"2"
CL-USER> (generate-captcha)
"what is 7 times 7?"
"49"
CL-USER> (generate-captcha)
"what is 4 minus 7?"
"-3"
CL-USER> (generate-captcha)
"what is 5 plus 1?"
"6"
CL-USER> (generate-captcha)
"what is 6 minus 1?"
"5"
CL-USER>