A - B = B

B * C = A

D : B = E

C * C = E

C + E = A

For which numbers stand A, B, C, D and E?

A perfect number is a number which is equal to the sum of all its divisors. For example 6 is divisable by 1,2,3 and 1 + 2 + 3 = 6. Can you find another perfect number?

In the morning a green-grocer puts 200 kg cucumbers outside in front of his shop. These cucumbers consists for 99% out of water. Because it is a warm day some water will evaporate. As a result, at the end of the day the cucumbers consist for 98% out of water. How many kg's of these cucumbers are left at the end of the day?