Question
Five years ago, the average age of a family of
four members was 25 years. Six years hence, the ratio of their ages will be 9:7:5:3. Find the approximate present ages of each family member.Solution
Let the ages of the four family members be A, B, C, and D, respectively. Five years ago, the average age of a family of four members was 25 years: The total age of the family five years ago = 4 Γ 25 = 100 The sum of their ages five years ago = A + B + C + D = 100 The total present age of the family = (A + 5) + (B + 5) + (C + 5) + (D + 5) = 100+20 =120 Six years hence, The total age of the family =(A+5+6) + (B+5+6) + (C+5+6) + (D+5+6) = 120+24 =144 Six years hence, the ratio of their ages will be 9:7:5:3 (9x) + (7x) + (5x) + (3x) = 144 x = 144 / 24 x = 6 A = 9x β 6 = (9 Γ 6) - 6 = 54 β 6 = 48 years B = 7x β 6 = (7Γ 6) β 6 = 42- 6 = 36 years C = 5x β 6 = (5 Γ 6) - 6 = 30 β 6 = 24 years D = 3x β 6 = (3 Γ 6) - 6 = 18 β 6 = 12 years
- 50% of the work done by Meena in 2 days is equal to 25% of the work done by Lata in 5 days. If Meena can complete the job alone in 10 days, then how long w...
- Pipes X and Y can fill a tank in 48 minutes and 80 minutes respectively. Another pipe Z can empty the tank in 2 hours. X and Z are opened together. If afte...
- Varun and Arnav can finish a work in 28 days and 56 days respectively when working alone. Varun starts first. In how many days should Arnav join him so tha...
A and B can complete a work together in 20 days. If A alone can complete one-fourth of the work in ‘x’ days and remaining work is completed ...
'G', 'H', and 'I', working together, can finish a task in 6 days. 'G' and 'H' can do it in 7.2 days, and 'H' and 'I' in 9 days. How long would it take f...
There is enough food in a camp to last for 50 days if each of the 80 soldiers present at the camp eat 2 times a day. After 20 days, 30 soldiers left th...
40 men can complete a piece of work in 48 days. βxβ men started the work and after 30 days 56 more men joined them so that whole work was finished i...
A can do a piece of work in 15 days, B is 25% more efficient than A, and C is 40% more efficient than B. A and C work together for 3 days and then C lea...
1 man and 4 women can complete a work in 65 /4 days, while 3 men and 4 women can complete it in 13 /2 days. In whom many days will be 13 women complete ...
Karan, Arjun and Krunal alone can complete a work in 35, 70 and 60 days respectively. All of them started working together but after 3 days from start K...