The Exact Age?

Tommy: "How old are you, Mamma?"

Mamma: "Let me think, Tommy. Well, our three ages add up to exactly seventy years."

Tommy: "That's a lot, isn't it? And how old are you, Papa?"

Papa: "Just six times as old as you, my son."

Tommy: "Shall I ever be half as old as you, Papa?"

Papa: "Yes, Tommy; and when that happens our three ages will add up to exactly twice as much as to-day."

Tommy: "And supposing I was born before you, Papa; and supposing Mamma had forgot all about it, and hadn't been at home when I came; and supposing..."

Mamma: "Supposing, Tommy, we talk about bed. Come along, darling. You'll have a headache."

Now, if Tommy had been some years older he might have calculated the exact ages of his parents from the information they had given him. Can you find out the exact age of Mamma?

Here is CALCULATION of exact age!

Calculation Of The Exact Age

What was the problem? 

Let us suppose T be the age of Tommy, M be of the Mamma and P be that of Papa.

Sum of their ages is 70.

T + M + P = 70  ......(1)

and Papa is 6 times as old as Tommy,

P = 6T  .....(2)

In unknown number of years X, Papa will be twice old as Tommy,

P + X = 2 (T + X)  ....(3)

and the sum of ages at that time is 70 x 2 = 140,

(T + X) + (P + X) + (M + X) = 140.

T + P + M + 3X = 140

From (1), above equation becomes,

70 + 3X = 140

X = 70/3     .....(4)

Putting (4) and (2) in (3),

P + X = 2 (T + X) 

6T + 70/3 = 2(T + 70/3)

T = 70/12    .....(6)

Using (6) in (2),

P = 6T

P = 6(70/12)

P = 70/2    ......(7)

Putting (6) and (7) in (1),

M = 70 - 70/2 - 70/12

M = 29.1666 = 29 years 2 months.

P = 70/2 = 35 years.

T = 70/12 = 5.8333 = 5 years 10 months.

 
To summarize, the Tommy is 5 years 10 months old, Mama is 29 years 2 months old and Papa is 35 years old.

50th Fastest And The 50th Slowest

Matt is the fiftieth fastest and the fiftieth slowest runner in his school.

Assuming no two runners are the same speed, how many runners are in Matt’s school?

Find here total number of runners! 

Total Runners In The School

Read the given data first!
 
This could be very tricky one. Let's assume that the Matt is fifth fastest and fifth slowest runner in his school.

Then there are 4 runners ahead of him numbered 1 to 4 and 4 behind him numbered 6 to 9. So there would be total 9 runners in his school in the case.

But Matt is 50th fastest runner meaning 49 are ahead of him numbered 1 to 49. And 49 are behind him numbered as 51 to 99 (total 49) while Matt is at 50th position.

Hence, there are 49 + 1 + 49 = 99 runners in his school.