Tutor MathsGuru: Ask me for your burning Maths questions!

[MathIzzzFun]

YumYum:

Hi,

Wld appreciate help on these Qns:

1. The ratio of the number of angelfish to the number of goldfish in tank A was 9:4. When 60 angelfish and 30% of the goldfish were transferred to tank B, the ratio of the no. Of angelfish to the no. Of goldfish in tank A became 15:7. How many fish were transferred from tank A to tank B?

Thanks

Hi

Initially, angelfish : goldfish (tank A) = 9u : 4u
After transfer to Tank B,
angelfish in tank A = 9u - 60,
goldfish in tank A = 0.7 x 4u = 2.8u

so, we have
9u - 60 : 2.8u
= 15 : 7

cross-multiply: 63u - 420 = 42u, 21u = 420
1u = 20

Number of goldfish transferred to Tank B = 0.3 x 4u = 0.3 x 4 x 20 = 24

cheers.

[Essential]

Sorry math is fun, did not get the message from u

[MathIzzzFun]

Essential:

Sorry math is fun, did not get the message from u

Hi

could you check your \"My Private Messages\" after you sign in.. alternatively, you could also click on \"messages\" at the top of the Forum page.

cheers.

[concern_mum]

HI, how to add 1+3+5+7+9+…99

[Tutor21]

concern_mum:

HI, how to add 1+3+5+7+9+....................99

Sequence : 1 + 3 + 5 …..49 + 51…….95 + 97 + 99

Add directly opposite numbers,
1 + 99 = 100
3 + 97 = 100
5 + 95 = 100
.
.
.
49 + 51 = 100

1 to 100 has a total of 100 numbers; 50 pairs
1 to 100 has a total of 50 odd numbers; 25 pairs

Thus total sum of sequence (1+3+5+7+9+....................99) = 100 x 25 = 2500

[shruthi]

A simple looking question.but dont understand.pls explain.A travels from P to Q in 2 hrs.B travels from Q to P in 4 hours.Both started at 2pm.what time did they meet

[MathIzzzFun]

shruthi:

A simple looking question.but dont understand.pls explain.A travels from P to Q in 2 hrs.B travels from Q to P in 4 hours.Both started at 2pm.what time did they meet

Hi

you may want to look at the distance each travel in 1 hour, it would help if you draw a diagram:

In 1 hour, A travel 1/4 of the distance & B travels 1/2 of the distance. Total distance travelled by both in 1 hour
= 1/4 + 1/2 = 3/4 of the distance between P & Q

when they meet each other, total distance travelled = distance between P & Q. So, time taken = 4/3 h = 1h 20 min

Time when they meet = 2pm + 1h 20 min = 3.20pm

cheers.

[concern_mum]

hi, can you show me in detail how to solve below question?


The ratio of Atrirah’s monety to Malek’s money was 3:5
After Malek spent $42, the ratio of Atirah’s money to Malek’s money became 9:8
How much money did Malek have left?

[concern_mum]

hi, 1 more question i need help.


There are twice as many 20 cent coin as 50 cents coins in a piggy bank. The total value of the coins is $63. How manu coins are there altogether.

[MathIzzzFun]

concern_mum:

hi, can you show me in detail how to solve below question?


The ratio of Atrirah's monety to Malek's money was 3:5
After Malek spent $42, the ratio of Atirah's money to Malek's money became 9:8
How much money did Malek have left?

Hi

Only Malek spent money, so Atrirah's money will remain the same. So, make Atrirah's share the same - drawing a model will help to \"see\".

After Malek spent $42, Atrirah : Malek = 9u : 8u
Before Malek spent the money, Atrirah : Malek = 3: 5 = 9u:15u
So, Malek spent 15u-8u=7u = $42, 1u = $6.
Malek had 15u left --> 15 x $ 6 = $90.

cheers.