Question 5
The numbers 90, 92, 94, 96 and 98 are written on five cards. A student draws one of them at random, and then she writes down three numbers. The first number written can be chosen arbitrarily by the student except that it must be larger than the number on her card. The second number is the difference between the first number and the number on her card. The third number is the sum of the first number and the number on her card. For which number on her card is it impossible for three prime numbers to be written down?