Total of 6 numbers = 6 × 12 = 72. After removing 18, remaining sum = 72 − 18 = 54. New average = 54 ÷ 5 = 10.8.
7454
In a TV factory, an average of 60 TVs are produced per day for the first 25 days of a month. Due to illness, the monthly average drops to 58 TVs per day over 30 days. What was the average production for the last 5 days?
Total production for 30 days = 30 × 58 = 1740. Production for first 25 days = 25 × 60 = 1500. Remaining production = 1740 − 1500 = 240. Average for last 5 days = 240 ÷ 5 = 48.
7455
The average salary of 20 workers in an office is Rs. 1900 per month. If the manager’s salary is included, the average becomes Rs. 2000. What is the manager’s annual salary?
With an average speed of 40 km/h a train reaches its destination on time. If it travels at 35 km/h, it arrives 15 minutes late. What is the distance of the journey?
Let distance = d. Time difference = (d/35 − d/40) = 15 minutes = 0.25 hour. Simplifying gives (5d / 1400) = 0.25 → d = 70 km.
7457
The average expenditure of a man for the first five months is Rs. 120 and for the next seven months it is Rs. 130. If he saves Rs. 290 in the year, what is his average monthly income?
Total expenditure = (5 × 120) + (7 × 130) = 600 + 910 = 1510. Total income = 1510 + 290 = 1800. Average monthly income = 1800 ÷ 12 = 150.
7458
The average marks obtained by 120 candidates was 35. If the average of passed candidates was 39 and that of failed candidates was 15, how many candidates passed?
Let passed candidates = x. Failed = 120 − x. Total marks = 120 × 35 = 4200. Equation: 39x + 15(120 − x) = 4200 → solving gives x = 100.
7459
The average monthly income of a family of four earning members was Rs. 735. After one member died, the average income became Rs. 650. What was the income of the deceased member?
Total income of 4 members = 4 × 735 = 2940. Income of remaining 3 members = 3 × 650 = 1950. Income of deceased member = 2940 − 1950 = 990.
7460
On a journey across a city, a taxi travels 60% of the distance at 30 km/h, 20% at 20 km/h, and the remaining 20% at 10 km/h. What is the average speed for the whole journey?
