Answer the questions $12-17$ using the Case given below. $(25$ p$)$

In August, Walton Bookstore must decide how many of next year's nature calendars to order. Each calendar

costs the bookstore $$7,5$ and is sold for $$10.$ After February $1,$ all unsold calendars will be returned to the

February $1$ follows the of $$2,5$ per calendar. Walton believes that the number of calendars it can sell by

model to help it decide how many calendars to order. value $=1,96)$

Write the formula in cell $B19.(4p)$

Write the formula in cell $C19.(4$ p$)$

Write the formula in cell D$19.(4$ p$)$

Write the formula in cell F$19.(4$ p$)$

Write the formula in cell B$13.(4$ p$)$

Write the formula in cell E$13.(5$ p$)$