Richiez:


Here is the way to solve questions like this.
we know that compound amount (not periodical)
A= P(1+r)^t
compound interest C therefore is A-P
=P(1+r)^t-P
C=P[(1+r)^t-1]
making P subject formula
P=C/[(1+r)^t-1]........................(1)

for sake of convenience, let 't' for compound interest =t₁

P=C/[(1+r)^t₁-1]..............................(2)

on the other hand, simple interest

I= P x t x r..................................(3)
also let t=t₂

P = I/(t₂ x r) ......................(4)

note that although time is different for both, rate is the same.

equating value of P in (2) & (4)

C/[(1+r)^t₁-1] = I/(t₂ x r)

153/[(1+r)²-1] =225/(3 x r)

459r = 225[1+2r+r² -1]

225r² + 450r - 459r =0

225r² = 9r
225r = 9
r = 9/225 = 0.04 = 4%

now let's insert the value of r in eqn(4)
P = I/(t₂ x r)

P = 225/(3 x 4%)

P= 225/(3 x 0.04)

Principal amount= N1,875

labodinho: Mathz Guru will always be maths guru.Can u please allow me to call this thread MATHS HOSPITAL cos we've gat great maths Doctors here....................................Ma qustn goes thus:-----Simple interest on a certain sum of money for 3 years is N225 and the compound interest on the same sum at the same rate for 2 years is N153.Then the principle invested is?

Richiez:
The above is also referred to as the exponential shift rule.
before I start solving the question, I'd like to make a little correction in the question. so Mr. Honey take note; the question ought to be
1/(ΦD)(e^px*F(x))=(e^px)*1/Φ(D+p)*F(x)

let me know if you agree with the above correction so I can post the answer

labodinho: Sir Richie, can u check your working again?I do agree with Ortarico.

Richiez:


Here is the way to solve questions like this.
we know that compound amount (not periodical)
A= P(1+r)^t
compound interest C therefore is A-P
=P(1+r)^t-P
C=P[(1+r)^t-1]
making P subject formula
P=C/[(1+r)^t-1]........................(1)

for sake of convenience, let 't' for compound interest =t₁

P=C/[(1+r)^t₁-1]..............................(2)

on the other hand, simple interest

I= P x t x r..................................(3)
also let t=t₂

P = I/(t₂ x r) ......................(4)

note that although time is different for both, rate is the same.

equating value of P in (2) & (4)

C/[(1+r)^t₁-1] = I/(t₂ x r)

153/[(1+r)²-1] =225/(3 x r)

459r = 225[1+2r+r² -1]

225r² + 450r - 459r =0

225r² = 9r
225r = 9
r = 9/225 = 0.04 = 4%

now let's insert the value of r in eqn(4)
P = I/(t₂ x r)

P = 225/(3 x 4%)

P= 225/(3 x 0.04)

Principal amount= N1,875

Ortarico:

Oga laboz, this your question should be for the economists. Hmmmmm. . . .

First of all, let's find the S.I for a particular year i.e the S.I in a year = #225/3 = #75

Now at a compound interest of #153 at the same rate for 2yrs = #75 x 2 = #150
subtract that from the C.I = #153 - #150 = #3. . .i.e #3 extra interest over #75
Thereafter we find the %interest rate = 3/75 x 100 = 4%

Finally, denote the principal he raised in the first year as 'x';
:. 75 = 4% of x
75 = 4/100*x
7,500 = 4x
x = 1,875
:. The principal is #1,875

To check this apply the S.I = PRT/100 formula, where P = 1,875, R = 4% and T = 3 to get back #225 simple interest.

honey: ok, thats true, thanks anyway

Richiez:

Hope you are now okay with this working...cos it's extremely correct

benbuks: Sm ppl gave birth 2 math. Dey tot, dey gave birth 2 a baby...i cnt lie 2u guys...i remove my cap 4 una oo. Expecially.master ,prof. Richez..

shollynoob: Oga Richiez i salute o, i have never post a question here but am following this thread. please, for how long u have been solving maths, and hw did you learn all these concept, chai i dey jealous o

benbuks: Sm ppl gave birth 2 math. Dey tot, dey gave birth 2 a baby...i cnt lie 2u guys...i remove my cap 4 una oo. Expecially.master ,prof. Richez..

Mr Calculus: oga i join u o..no b small tin

chintzs: I desperatly need help,cause I just got admission into the university to come study maths,buh I'm scared..I didn't choose the course initially,however I think its was due to my postutme mark.....all I need from y'all a lil tip/adivise,cause I wanna do well I school!!! But d most frustrating thing is "I knw nofing bout the course"

Richiez:

Here are a few tips;
1. you have to develop a great interest for math, and have that strong desire to become a maths guru.

2. Realize that there's nothing magic about mathematics.

3. make friends with people who appreciate mathematics.

4. practise as many maths questions as possible, starting from the very simple ones to more complex ones. develop the urge to solve them on your own, but you can always seek for assistance whenever you get hooked.

5. do not forget any new thing you have learnt, keep reviewing them.

6. learn to memorize some basic maths formulas as this will build your confidence.

7. Finally stick to this thread...as much as you want to learn, also develop the urge to want to contribute

GOOD LUCK

Richiez:

chintzs: [/color][color=#990000]lolz its seems yu've got this rep written somewhere,because I could. Tell yu about the numerous times av seen on this threEad....fanks anyway but I was expecting somethingg more...

chintzs: [/color][color=#990000]lolz its seems yu've got this rep written somewhere,because I could. Tell yu about the numerous times av seen on this threEad....fanks anyway but I was expecting somethingg more...

benbuks: ...my bible says trust in the lord with all your heart(proverb 3:5) ...paul the apostle also says dat.." i can do all things through christ who gives me strength..".....u c life itself its mathematical.....math is nt just solvin complex eqaution..or plotin graphs...note dat .every.mathematical problem have a real life application...to be a math genius..u shud nt just be solvin simple problems..but try d tough ones..by so doing..u r xpanding..ur brain..n boosting ur IQ....AND ALSO REMEMEBER THAT THE MARK OF A TRUE HERO IS HUMMILITY...ALWAYS BRING YOURSELF DOWN TO Learn.....dnt be a talkative...rational thinkers dnt talk too much.....girls cud be a distraction u kw,B-) ........

Richiez:
Our spokesman has said it all....God first! Courage, determination, perseverance, humility and discipline all have their own part to play...nice one benbuks

Richiez:

Nice job bro!

Boladearo: @odehfamily
salem:sunday = 200k:50k = 100K:25K
Therefore for every 1naira that salem gets sunday is given 25k i.e 1/4naira
Sunday:shaka= N4:N2 = 2:1
i.e for every N1 sunday gets shaka get N1/2
salem:sunday: shaka= 1:1/4;1/2*1/4 = 1:1/4 :1/8 multiply tru by 8 (LCM)
salem ; sundea : shaka = 8 : 2 : 1
skaka's share = 1/11 *1100 = 100
My oga's at the tower, am i right.

Boladearo: @odehfamily
salem:sunday = 200k:50k = 100K:25K
Therefore for every 1naira that salem gets sunday is given 25k i.e 1/4naira
Sunday:shaka= N4:N2 = 2:1
i.e for every N1 sunday gets shaka get N1/2
salem:sunday: shaka= 1:1/4;1/2*1/4 = 1:1/4 :1/8 multiply tru by 8 (LCM)
salem ; sundea : shaka = 8 : 2 : 1
skaka's share = 1/11 *1100 = 100
My oga's at the tower, am i right.

Odehfamily: Good day ever1. Plz,somebody shld plz assist me wif this questn.
salem,sunday and shaka shared the sum of N1,100 for every N2 that salem gets sunday gets 50kobo and for every N4,sunday gets shaka gets N2. Find shaka's share

Boladearo: @odehfamily
salem:sunday = 200k:50k = 100K:25K
Therefore for every 1naira that salem gets sunday is given 25k i.e 1/4naira
Sunday:shaka= N4:N2 = 2:1
i.e for every N1 sunday gets shaka get N1/2
salem:sunday: shaka= 1:1/4;1/2*1/4 = 1:1/4 :1/8 multiply tru by 8 (LCM)
salem ; sundea : shaka = 8 : 2 : 1
skaka's share = 1/11 *1100 = 100
My oga's at the tower, am i right.

Odehfamily: Abeg please help me out again.
2/root 3(2/root 3-root 12/6). Solve wifout using cal.or table.