The answer is 5 cents because if the bat is a dollar more, then it the bat would be $1.05, and 0.05 + 1.05 = $1.10
you could also use the equation x + (x + 1) = 1.10 where x is the cost if the ball and x + 1 is the cost of the bat. x + x + 1 is the same as 2x + 1 = 1.10, and when solved x = 0.05.
if the order mattered it would be 7*6*5 *4*3 = 2520 arrangements
if order didn't matter
7*6*5*4*3*2 divided by (5*4*3*2*2) = 21
It should be 270 since 6 x 9 x 10 x 1/2= 270