Y is indirectly proportional to x. when y=7, x=9
a) work out an equation connecting y and x.
b) work out the value of y when x=21

The sum of the speeds of two trains is 720.2 mph. if the speed of the first train is 7.8 mph faster than the second train, find the speeds of each.

Nicole is making carrot bread she needs 5 cups of carrots for 2 cups of sugar.what is the ratio of cups of sugar to cups of carrots that nicole will need? write the ration in three different ways

Adele is five years older than timothy. in three years, timothy will be 2/3 of adele’s age. what is adele‘s current age?