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Senior three mathematics examination paper liberal arts answer
The height of the flag is H.

Then the distance from the person in the first row to the bottom of the flagpole is s 1=h/tan60.

The distance from the person in the last row to the flagpole is s2=(h- 10)/tan 30.

Square root of S2-s1=106cos15.

The square root of (h- 10 radical 6sin15)/tan30-h/tan60 =106cos15.

Root number 3h- 10 6 * root number 3 (root number 2 of 6) /4-h* root number 3/3 = 10 6 * (root number 2 of 6)/4.

(2/3 root number 3)h- 15 root number 3+ 15= 15+5 root number 3

H=(20 elements 3)*3/(2 elements 3) = 30m.

Therefore, the average speed v = h/t = 30/50 = 3/5m/s.

Option a