To make one cheese sandwich, tina uses one bread roll and two cheese slices.
pack of 15 bread rolls £2.23. pack of 20 cheese slices £1.91 she is going to buy enough packs to have exactly twice as many cheese slices as bread rolls make more than 100 cheese sandwiches. work out the least amount she can spend.

The position of a moving particle is given by the position function: f(t)=-9t-t^2-0.2t^3+0.1t^4 0 a. at what time does the particle reverse direction? b. when is the displacement positive? (round one decimal place and answer in interval notation) c. when is the displacement negative? (round one decimal place and answer in interval notation) d. when is the particle’s acceleration positive? (round one decimal place and answer in interval notation) e. when is the particle’s acceleration negative? (round one decimal place and answer in interval notation)