Passing through (1,9) parallel to y=5x+6

This race was first held in 1953 on august 16th. every decade the race finishes with a festival. how many years is this?

If cos(2x) = tan^2(y), show that cos(2y) = tan^2(x).

Acompany manufactures three types of cabinets. it makes 110 cabinets each week. in the first week, the sum of the number of type-1 cabinets and twice the number of type-2 cabinets produced was 10 more than the number of type-3 cabinets produced. the next week, the number of type-1 cabinets produced was three times more than in the first week, no type-2 cabinets were produced, and the number of type-3 cabinets produced was the same as in the previous week.