RRB NTPC · Question 44
Direction: Answers to the following questions are based on the details given below: In a city with 120 families, 93 families use biogas, 63 use LPG gas, 45 use wood, 45 use biogas and LPG gas, 24 use LPG of gas and wood and 27 of families use wood and biogas for cooking. How many families use LPG gas, biogas and wood? A. 5 B. 10 C. 15 D. 2
Show answer & explanation
Answer: (B) C
Explanation
With every family using at least one fuel: 120 = 93 + 63 + 45 − 45 − 24 − 27 + x, so 120 = 105 + x and x = 15 families use all three.