Background: Lactose intolerance is due to the lack of enzyme lactase in the small intestines to break lactose down into glucose and galactose.[3] There are four types: primary, secondary, developmental, and congenital.[1] Primary lactose intolerance occurs as the amount of lactase declines as people age.[1] Secondary lactose intolerance is due to injury to the small intestine such as from infection, celiac disease, inflammatory bowel disease, or other diseases.[1][4] Developmental lactose intolerance may occur in premature babies and usually improves over a short period of time.[1] Congenital lactose intolerance is an extremely rare genetic disorder in which little or no lactase is made from birth.[1]

Situation: David works for a large pharmaceutical company as a research scientist. He has devised a procedure which can detect lactose intolerance in patients easily. To test his procedure he picked up four subjects form a large pool of sample. The four subjects are subject A, subject B, subject C, and subject D. Subject A has primary lactose intolerance; subject B has secondary lactose intolerance; subject C has developmental lactose intolerance; and subject D has congenital lactose intolerance.

Question: Which subject would most porbably be older, subject A or subject C?
Answer: subject A

Situation: David works for a large pharmaceutical company as a research scientist. He has devised a procedure which can detect lactose intolerance in patients easily. To test his procedure he picked up four subjects form a large pool of sample. The four subjects are subject A, subject B, subject C, and subject D. Subject A has primary lactose intolerance; subject B has secondary lactose intolerance; subject C has developmental lactose intolerance; and subject D has congenital lactose intolerance.

Question: Which subject would most porbably be younger, subject A or subject C?
Answer: subject C

Situation: David works for a large pharmaceutical company as a research scientist. He has devised a procedure which can detect lactose intolerance in patients easily. To test his procedure he picked up four subjects form a large pool of sample. The four subjects are subject A, subject B, subject C, and subject D. Subject A has primary lactose intolerance; subject B has secondary lactose intolerance; subject C has developmental lactose intolerance; and subject D has congenital lactose intolerance.

Question: Would subject A be younger or older than subject C?
Answer: older

Situation: David works for a large pharmaceutical company as a research scientist. He has devised a procedure which can detect lactose intolerance in patients easily. To test his procedure he picked up four subjects form a large pool of sample. The four subjects are subject A, subject B, subject C, and subject D. Subject A has primary lactose intolerance; subject B has secondary lactose intolerance; subject C has developmental lactose intolerance; and subject D has congenital lactose intolerance.

Question: Would subject C be younger or older than subject A?
Answer: younger

Situation: David works for a large pharmaceutical company as a research scientist. He has devised a procedure which can detect lactose intolerance in patients easily. To test his procedure he picked up four subjects form a large pool of sample. The four subjects are subject A, subject B, subject C, and subject D. Subject A has primary lactose intolerance; subject B has secondary lactose intolerance; subject C has developmental lactose intolerance; and subject D has congenital lactose intolerance.

Question: Which subject has lactose intolerance due to an injury, subject B or subject D?
Answer: subject B

Situation: David works for a large pharmaceutical company as a research scientist. He has devised a procedure which can detect lactose intolerance in patients easily. To test his procedure he picked up four subjects form a large pool of sample. The four subjects are subject A, subject B, subject C, and subject D. Subject A has primary lactose intolerance; subject B has secondary lactose intolerance; subject C has developmental lactose intolerance; and subject D has congenital lactose intolerance.

Question: Which subject has lactose intolerance due to genetic disorder, subject B or subject D?
Answer: subject D

Situation: David works for a large pharmaceutical company as a research scientist. He has devised a procedure which can detect lactose intolerance in patients easily. To test his procedure he picked up four subjects form a large pool of sample. The four subjects are subject A, subject B, subject C, and subject D. Subject A has primary lactose intolerance; subject B has secondary lactose intolerance; subject C has developmental lactose intolerance; and subject D has congenital lactose intolerance.

Question: Which subject's condition would improve over time, subject A or subject C?
Answer: subject C

Situation: David works for a large pharmaceutical company as a research scientist. He has devised a procedure which can detect lactose intolerance in patients easily. To test his procedure he picked up four subjects form a large pool of sample. The four subjects are subject A, subject B, subject C, and subject D. Subject A has primary lactose intolerance; subject B has secondary lactose intolerance; subject C has developmental lactose intolerance; and subject D has congenital lactose intolerance.

Question: Which subject's condition would deteriorate over time, subject A or subject C?
Answer: subject A

Situation: David works for a large pharmaceutical company as a research scientist. He has devised a procedure which can detect lactose intolerance in patients easily. To test his procedure he picked up four subjects form a large pool of sample. The four subjects are subject A, subject B, subject C, and subject D. Subject A has primary lactose intolerance; subject B has secondary lactose intolerance; subject C has developmental lactose intolerance; and subject D has congenital lactose intolerance.

Question: Would subject A's condition improve or deteriorate over time?
Answer: deteriorate

Situation: David works for a large pharmaceutical company as a research scientist. He has devised a procedure which can detect lactose intolerance in patients easily. To test his procedure he picked up four subjects form a large pool of sample. The four subjects are subject A, subject B, subject C, and subject D. Subject A has primary lactose intolerance; subject B has secondary lactose intolerance; subject C has developmental lactose intolerance; and subject D has congenital lactose intolerance.

Question: Would subject C's condition improve or deteriorate over time?
Answer: improve