Question
The average age of a group of
five friends is 78 years. If a friend, aged 48 years, is replaced by another friend, then the average age of each friend in the group will increase by 4 years. Find the age of the friend who was replaced.Solution
ATQ,
Sum of the ages of 5 friends, initially = 5 X 78 = 390 years Let the age of the new friend who joined the group = 'y' years Therefore, 390 - 48 + y = 5 X (78 + 4) Or, 'y' = 410 - 342 = 68 Therefore, age of the new friend = 68 years Alternate Solution Age of the new friend = age of the friend replaced + increase in average age X number of friends So, age of the new friend = 48 + 5 X 4 = 48 + 20 = 68 years
564.932 + 849.029 – 425.08 = 612.095 + ?
999.99 + 99.99 + 99= ?
A sum of ₹60,000 is invested at a compound interest rate of 'x%' per annum, compounded annually, and grows to ₹75,264 in 2 ye...
What approximate value will come in place of the question mark (?) in the following question? (Note: You are not expected to calculate the exact value.)...
³√? × 33.97 + 59.99 × 28.9 – 48.98 × 21.42 = 1085.344
1279.98 ÷ 40.48 × 10.12 = ? × 2.16
(124.901) × (11.93) + 219.95 = ? + 114.891 × 13.90
What approximate value will come in place of the question mark (?) in the following question? (Note: You are not expected to calculate the exact value.)...
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