TASK DEFINITION: This task is about creating an unanswerable question based on a given passage. Construct a question that looks relevant to the given context but is unanswerable. Following are a few suggestions about how to create unanswerable questions:
(i) create questions which require satisfying a constraint that is not mentioned in the passage
(ii) create questions which require information beyond what is provided in the passage in order to answer
(iii) replace an existing entity, number, date mentioned in the passage with other entity, number, date and use it in the question
(iv) create a question which is answerable from the passage and then replace one or two words by their antonyms or insert/remove negation words to make it unanswerable.
PROBLEM: Passage: Double fertilization refers to a process in which two sperm cells fertilize cells in the ovary. This process begins when a pollen grain adheres to the stigma of the pistil (female reproductive structure), germinates, and grows a long pollen tube. While this pollen tube is growing, a haploid generative cell travels down the tube behind the tube nucleus. The generative cell divides by mitosis to produce two haploid (n) sperm cells. As the pollen tube grows, it makes its way from the stigma, down the style and into the ovary. Here the pollen tube reaches the micropyle of the ovule and digests its way into one of the synergids, releasing its contents (which include the sperm cells). The synergid that the cells were released into degenerates and one sperm makes its way to fertilize the egg cell, producing a diploid (2n) zygote. The second sperm cell fuses with both central cell nuclei, producing a triploid (3n) cell. As the zygote develops into an embryo, the triploid cell develops into the endosperm, which serves as the embryo's food supply. The ovary now will develop into fruit and the ovule will develop into seed.

SOLUTION: When a pollen tube fertilizes cells in the ovary, what is it called?

PROBLEM: Passage: Mastic asphalt is a type of asphalt which differs from dense graded asphalt (asphalt concrete) in that it has a higher asphalt/bitumen (binder) content, usually around 710% of the whole aggregate mix, as opposed to rolled asphalt concrete, which has only around 5% added asphalt/bitumen. This thermoplastic substance is widely used in the building industry for waterproofing flat roofs and tanking underground. Mastic asphalt is heated to a temperature of 210 C (410 F) and is spread in layers to form an impervious barrier about 20 millimeters (0.79 inches) thick.

SOLUTION: What percentage of concrete is in mastic asphalt?

PROBLEM: Passage: The Pentagon bought 25,000 MRAP vehicles since 2007 in 25 variants through rapid acquisition with no long-term plans for the platforms. The Army plans to divest 7,456 vehicles and retain 8,585. Of the total number of vehicles the Army will keep, 5,036 will be put in storage, 1,073 will be used for training, and the remainder will be spread across the active force. The Oshkosh M-ATV will be kept the most at 5,681 vehicles, as it is smaller and lighter than other MRAPs for off-road mobility. The other most retained vehicle will be the Navistar MaxxPro Dash with 2,633 vehicles, plus 301 Maxxpro ambulances. Thousands of other MRAPs like the Cougar, BAE Caiman, and larger MaxxPros will be disposed of.

SOLUTION:
How many MRAP vehicles has the pentagon bought since 2000?