Jen, carrie, and fran are each thinking of a number.
Let the number Jen thinks is J
Let the number Carrie thinks is C
Let the number Fran thinks is F
when you add their numbers together you get 207
so J + C + F = 207 -------------> Equation 1
jen's number is 9 more than carrie's
So J = 9 + C -------------> Equation 2
and fran's number is 3 less than jen's number
So F = J - 3
Replace 9 + C for J
F= 9 + C - 3 = 6 + C ------------> Equation 3
Replace equation 2 & 3 in equation 1
J + C + F = 207
9 + C + C + 6 + C = 207
3C + 15 = 207
3C = 192
Divide by 3 on both sides
C = 64
We know F = 6 + C = 6 + 64 = 70
So Fran's number = 70