7) Why did Revere need a signal from the Old North Church?

Why did Revere need a signal from the Old North Church?

"This signal, from the tallest structure in the town of Boston, served as an early warning that a detachment of the British Army was crossing the Charles River and heading west towards the towns of Lexington and Concord. By the end of the next night, the American Revolutionary War had begun."

The place for the signal, the Old North Church in Boston's North end was chosen for two reason.

The signal was meant to warn patriots in Chalrestown, and across the river from Boston in case Paul Revere couldn't deliver the message there from Boston to start his ride.

the correct answer is:   "   3.6 % " .

          →   the unemployment rate is:   " 3.6 % " .

explanation:

to calculate the "unemployment rate" :

the "unemployment rate"   =

  [# of people unemployed] /   [working age population]   * 100 %   ;

                =   [9 million] / [250 million]     *   100 % ;

    →     note:   the units of "million" cancel out;

                    since:   " {million} / {million} = 1 " ;

                =   (9 / 250)   * 100 %   ;

                = 0.036 * 100 % ;

                =   3.6 %

answer:   the unemployment rate is:   " 3.6 % " .

im not sure on this one