how can i answer the following two problem?.?

Question

01.A train running at 7/11 of its own speed reached a place in 22 hours. How much time could be saved if the train would run at its own speed?.
(pls give answer with explanation)
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02.If the different between the compound interest,compounded every six months, and the simple interest on a certain sum of money at the rate of 12% per annum for one year is Rs 36/-. the sum is....?.
(pls give answer with explanation)

Answer 1

(1.)
22*7/11=x
x=14hrs (at actual speed)

22-14=8 hrs saved

(2.)
let x(1.12)^2 be the interest compounded every 6 months
let x(0.12) be the interest compounded every year

x(1.12)^2-x(0.12)=36
x=36/[(1.12)^2-0.12]

x(1.12)^2+x(0.12)=y
x[(1.12)^2+0.12]=y
{36/[(1.12)^2-0.12]}*[(1.12)^2+0.12]=y
y=43.62

Answer 2

1.
If the distances being run in both scenarios are the same, then using the distance formula D = VT, and setting D(1) = V(1)T(1) and D(2) = V(2)T(2), then D(1) = D(2), and V(1)T(1) = V(2)T(2).

From the above we derive this:

T(1) / T(2) = V(1) / V(2) ----> T(1) = T(2)[V(1) / V(2)].

If we let T(2) be the time it took for the train to reach its destination at V(2) = 7/11 its maximum speed, V(1), then the equation directly above becomes:

T(1) = 22[7/11V(1) / V(1)] = 22(7/11)[V(1) / V(1)] = 22(7/11) = 14.

So, the time it would take it to run the trip at full speed would be 14 hours, a savings of 8 hours.

2.
You need to re-post this question. Explain what Rs 36/- means and state exactly what sum you are looking for. My guess is that you are looking for the sum of money invested, but in order to figure that, the other things need to be clarified.

Answer 3

If the train runs at normal speed (faster), the new time would be reduced to 22*7/11 = 14, for a saving of 8 hours.

Answer 4

the way to find speed is u=x/t.
first time: 7/11u=x/22 (1)
second time: u=x/t (2)

(1)/(2)=> 7/11= t/22 <=> t=14h so he would save 22-14=8h

for 02 I cannot help you because English is not my mother language and I do not understand the words compound and annum.

Answer 5

The distance is the same
Let S = own speed
Let T = total time at its own speed.

Rate x time = Rate x time

(7/11) S x 22 = S x T

Solving for T:

14 S = T S

T = 14 hours

you would save 8 hours.


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Answer 6

7/11
7=22 which would make each unit aprox 3.14
7 x 3.14 =22
11 x 3.14 = 34.54
so 34.54 - 22 = 12.5