Katie hair grows 7/8 of a centimeter each month how many centimeters will katie hair grow over 5 months

If t17 = 3 (t5) in an arithmetic progression, find t1 in terms of d.

The moats separating people from the animals are 5 m wide for lions and 4 m wide for the elephants. if the lion’s moat is 4 m deep, how deep should the elephants’ moat be?

Ineed to know how to write question one in mathematical terms