250 से 1000 तक कितनी संख्याएँ 5, 6 और 7 से पुर्णतः विभाज्य हैं?

A number divisible by 5, 6 and 7 is a multiple of LCM = 210. Between 250 and 1000 these are 420, 630 and 840 – 3 numbers.