Question
There are 7 people in a group. Average age of the group
decreases by 5 when two more people join the group. Find the average age of the new group. Statement I: Sum of the ages of the two people who joined later is 25 yrs. Statement II: Total of the ages of people originally was 245 yrs. In each of the following questions, a question is followed by two statement. Read all the statements and find that which statements are required to answer the question and answer accordingly.Solution
From statement I: People becomes 9 from 7, and average decreases by 5. Let ‘n’ is previous average and then ‘n - 5’ is new average. So Sum of ages of 2 new people becomes 9 × (n – 5) – 7 × n which is given 25 So 9 × (n – 5) – 7 × n = 25 So 9n – 45 – 7n = 25 or 2n = 25+45= 70 So, n = 70/2 = 35 So average of new group = 35 – 5 = 30 From statement II: Total age of 7 people is 245 years, so their average = 245/7 = 35 So, average of new group = 35 – 5 = 30 So answer can be determined by either of statement I or II.
- Find the simplified form of the following expression:
128 - 85 of 2 + 26 X 4 4387897 – 3286871 – 51926 = ?
(22.5 × 24) ÷ 40 + 51.50 = ? ÷ 5.25
30% of 60% of 1800 + 13 × 14 = (? ÷ 75) × 5
25% of 400 + 3 × 102 = ?2Â
- Identify x such that x% of 540 plus {1080 ÷ x of 9} × 6 gives 162
(64/25)? × (125/512)?-1 = 5/8
36% of 640 – 12.5% of 352 + 25% of 640 = ? – 48% of 432
72 + 122 - 25% of 600 = ?
(168 ÷ 12 + 19 × 64)/(22+1) = ?