Tutor MathsGuru: Ask me for your burning Maths questions!

[jieheng]

lazy me:

Hi math guru,

Pls help me with this question:

There were 450 plastic chairs n metal chairs at a furniture store. After 60% of the plastic chairs n 1/6 of the metal chairs were sold, the total number of chairs left was 232. How many plastic chairs were sold?

---------at a store--------sold---------left
PC---------5u--------------3u------------2u
MC---------6p--------------1p-----------5p
Total-----450-------------218----------232

1p + 3u --> 218
6*(1p + 3u) --> 6*218
6p + 18u --> 1308
6p + 5u + 13u --> 1308
450 + 13u --> 1308
13u --> 858
1u --> 66

Number of plastic chairs were sold = 3u = 3*66 = 198

[nnchia]

Hi, need help on this question:-


Mrs. Tan bought 4 times as many toy guns as teddy bears. She spent $1750 altogether. A toy gun cost $10 less than a teddy bear. The total cost of toy guns was $490 more than the total cost of teddy bears.
(a) How much did Mrs. Tan spend on the teddy bears?
(b) How much did on teddy bear cost?

(Answer: (a) - $630, (b) - $18)

I could solve this via algebra but very lengthy so looking for a simpler solution! Thanks!

[jieheng]

nnchia:

Hi, need help on this question:-


Mrs. Tan bought 4 times as many toy guns as teddy bears. She spent $1750 altogether. A toy gun cost $10 less than a teddy bear. The total cost of toy guns was $490 more than the total cost of teddy bears.
(a) How much did Mrs. Tan spend on the teddy bears?
(b) How much did on teddy bear cost?

(Answer: (a) - $630, (b) - $18)

I could solve this via algebra but very lengthy so looking for a simpler solution! Thanks!

toy guns 4u
teddy bears 1u

total cost of teddy bears (1u) = (1750 - 490) / 2 = 630

a) the amount of money that Mrs. Tan spend on the teddy bears is $630

total cost of toy guns (4u) = 630 + 490 = 1120

the cost of toy guns (1u) = 1120 / 4 = 280

Difference between the cost of 1u of teddy bears and toy guns
=630 - 280
=350

Given the difference between the cost of 1 pc of teddy bear and toy gun
=10

No of teddy bears = 350 / 10 = 35

the cost of one teddy bear = 630 / 35 = 18

b) the cost of one teddy bear is $18

[nnchia]

Thank you so much for your reply!

[lazy me]

Tq jieheng for ur help!

[Herbie]

Hi! I need help in this qn.


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

[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]

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Hi, need help on this question. Thanks!