How many integers n satisfy 0 < n < 60 and 4n=6 (mod 7)
Because 2 and 7 are relatively prime, we can divide the congruence to get 2n=3 mod 7, and solving gets us n=5 mod 7. So, it is simply 5,12,19,26,33,40,47,54 for a total of 8 numbers.
+178 
