SAT Math Practice Question #25722 - SATify | SATify
#25722
number theory
digits
Totient Function
medium
120 sec
Let ♣(x) denote the sum of the digits of the positive integer x. For example, ♣(8)=8 and ♣(123)=1+2+3=6. For how many positive integers x such that 1≤x≤100 is ♣(♣(x))=2?