Both the leftmost digit and the rightmost digit of a four-digit number
n are equal to 1. when these digits are removed, the two-digit number
thus obtained is n ÷ 21. find n.

According to the general equation for conditional probability if p(anb)=3/7 and p(b)=7/8 what is p(a i b)

Express -5 2/5 as an improper fraction.

Candice uses the function f(t)=t+100−−−−−−√ to model the number of students in her after-school program. the variable t represents days and f(t) represents the number of students. how many days does it take for there to be 15 students in her program? a. 225 days b. 125 days c. 325 days d. 115 days