Question

Among 400 students in a college 310 use Wi-Fi, 210 use Data card and 150 use
GPRS, 150 students use both Wi-Fi and data card, 80 students use Data card and
GPRS and 90 use GPRS and Wi-Fi. Each student uses at least one service. How
many students use all the three services?

Answer 1

Answer:

i think all students use this all service