I think this is factorials
so an example would b....... 1*2*3*4*5.... ect
hope this helps
sara speed is half of Jeanette's so if jeanette ran 7 miles then her walking speed is 3.5MPH and sense she is 7 miles ahed sara is 10.5 miles behind... 3.5MPH which is jeanette speed is double than sara so 3.5/2 is 1.75MPH... Saras walking speed is 1.75MPH
25 x 4 equals 100. and 250 x 4 =1000. so one fourth of 1000 is 250.