Tutor MathsGuru: Ask me for your burning Maths questions!

[Herbie]

Hi! I need help in this qn.


In how many years will a sum double itself at 7.5% simple interest?
Tq

[nhps2012]

Can someone help me to solve this question? TIA


What is the maximum number of cylinders of height 6cm and diameter 4cm be placed into a box measures 21cm by 6cm by 12cm.

:thankyou:

[jieheng]

Herbie:

Hi! I need help in this qn.


In how many years will a sum double itself at 7.5% simple interest?
Tq

Amount = Principal + Interest

A = P + I
= P + (PRT)/100
= P ( 1 + R%*T)

When a sum double itself , A = 2P

2P = P ( 1 + 7.5%*T)

2 = 1 + 7.5%*T

T = 13 1/3 years = 13 years 4 months

[nnchia]

http://i43.tinypic.com/2e4vi1v.jpg\">

Hi, need help on this question. Thanks!

[jieheng]

nnchia:

http://i43.tinypic.com/2e4vi1v.jpg\">

Hi, need help on this question. Thanks!

Area Y - Area X = 13.5

(Area Y + Unshaded Area) - (Area X + Unshaded Area) = 13.5

1/2 *7*9 - (Length AB)*9 = 13.5

(Length AB)*9 = 31.5 - 13.5 = 18

Length AB = 18/9 = 2 cm

[starfish53]

Can anyone help me with the following question?


A fruit seller packed some oranges into 22 big carton boxes and 8 small carton boxes. There were 14 more oranges in a big carton box than in a small box. The ratio of number of oranges packed into big carton boxes to the number of oranges packed into small carton boxes was 3 : 1. How many oranges did the fruit seller pack altogether?

:thankyou:

[starfish53]

Can anyone help me with the following question?


Frederic had a candy bag which contained 35 chocolate bars and 50 sweets. Ryan had another candy bag which contained 45 chocolate bars and 10 sweets. After Frederic gave Ryan some chocolate bars and sweets, 40% of Frederic's candy bag contained chocolate bars and 30% of Ryan's candy bag contained sweets. How many chocolate bars and sweets did Frederic give to Ryan altogether?

:thankyou:

[nnchia]

Hi would appreciate help on part b http://i41.tinypic.com/33xijux.jpg\">

[Oldschool]

nnchia:

Hi would appreciate help on part b http://i41.tinypic.com/33xijux.jpg\">

Hi,

I presume all are straight lines.

Part (B) is by applying the principle of Part (A).

http://i43.tinypic.com/2loqbm.jpg\">

Therefore,

http://i40.tinypic.com/2j2eptz.jpg\">

Hence, (a + b + c + d + e + f) = 360

Regards

[excelquickly]

starfish53:

Can anyone help me with the following question?


A fruit seller packed some oranges into 22 big carton boxes and 8 small carton boxes. There were 14 more oranges in a big carton box than in a small box. The ratio of number of oranges packed into big carton boxes to the number of oranges packed into small carton boxes was 3 : 1. How many oranges did the fruit seller pack altogether?

:thankyou:

Hi,
As it is given ratio of big to small is 3:1
Using the model you will come up with will be:

http://i43.tinypic.com/2hzscxw.png\">

Looking at the model, you can see that two units is equivalent to 14. Thus you can tell that 1 unit is 7.

Therefore in a big box, there are 7X3 = 21 oranges
and in a small box there are 7 oranges.

22 big cartons= 21X 22 = 462
8 small cartons= 7 X 8 = 56
Total packed oranges will be 462+56=518

The working will be like this:
2 units = 14
1 unit = 7 (small carton)
3 units = 21 (Big carton)
22 big cartons = 22 X 21 = 462
8 small cartons = 8 X 7 = 56
Total oranges packed = 462+56 = 518

The fruit seller packed 518 oranges altogether.