Question
There were 24 students in the class. One of them, who
was 18 years old left the class and his place was filled up by a newcomer. If the average of the class was thereby lowered by 1 month, the age of the newcomer isSolution
Let the average age of 24 men be x ⇒ Sum of age of 24 men = 24x If a man replaced, then average age of 24 men = (x – 1/12) ⇒ If a man replaced, then sum of age of 24 men = 24 (x – 1/12) = 24x – 2 Let weight of new man be y According to the question 24x – 18 + y = 24x – 2 ⇒ y = 24x – 2 – 24x + 18 ⇒ y = 16 ∴ Age of new comer is 16 years.
3960, 660, 720, 122, 180, 30
2400,3600,5400,7200,12150
210, 140, 105, 84, 70, 63, 52.5
112, 236, 374, 546, 790, 1376
88, 112, 78, 120, 64, 136
Find the wrong number in the series.
3, 6, 18, 72, 360, 2160, 151202824 2314 1973 1759 1634 1574
120, 136, 111, 147, 93, 162, 81
Find the wrong number in given number series.
1116, 1135, 1158, 1187, 1224, 1278.
Find the wrong number in given number series.
2658, 2654, 2681, 2645, 2999, 2918