The sum "one + four = seventy" becomes correct if we replace each word by the number of letters in it to give 3 + 4 = 7. Using the same convention, which word could be substituted for x to make the sum "three + five = x" true?
Last week's solution:
180,000 per hour is equivalent to 3000 eggs per minute, i.e. to 50 eggs per second.
Source: UKMT