Maths Questions

1. C=car D=doll
3C-8D=96 (1)
C-D=67 (2)
From (2), C-D=67
D=C-67 (3)
Sub (3) into (1)
3C-8D=96
3C-8(C-67)=96
3C-8C+536=96
-5C=96-536
-5C=-440
C=88
the cost of the toy car is 88

2. R=red G=green
R=4G (1)
R=10(G-45) (2)
FROM (1), R=4G
G=R/4 (3)
Sub (3) into (2)
R=10(R/4-45)
R=10R/4-450
4R=10R-4(450)
4R-10R=-1800
-6R=-1800
R=300
the number of red buttons in the box is 300

3. T=Tim L=Lucy
T+L = 36 (1)
T+29=4L (2)
FROM (1), T+L=36
L=36-T (3)
Sub (3) into (2)
T+29=4L
T+29=4(36-T)
T+29=144-4T
T+4T=144-29
5T=115
T=23
Tim has 23 apples at first.
After receiving 29 apples from Mun, Tim has totally 52 apples

4. Q= Canton Q U= Canton U
Q+U=158 (1)
Q+47=U-47 (2)
FROM (1), Q+U=158
U=158-Q (3)
Sub (3) into (2)
Q+47 = U-47
Q+47 = 158-Q-47
2Q = 158-47-47
2Q = 64
Q = 32
there is 32 candles in Carton Q at first.
After transferring 47 candles from Carton U, there is totally 79 candles in Carton Q

5. H=Hudson S=Stuart
H=2S (1)
H-60=S/3 (2)
FROM (1), H=2S
S=H/2 (3)
Sub (3) into (2),
H-60=S/3
H-60=(H/2)/3
3(H-60)=H/2
6(H-60)=H
6H-360=H
6H-H=360
5H=360
H=72
Hudson has 72 marbles at first

1.The total cost of 3 toy cars is $96 more than the total cost of 8 dolls. Each toy car cost $67 more than each doll. Find the cost of each toy car.

3C-8C=96
C-D=67

2. The number of red buttons in a box is 4 times the number of green buttons in it. If 45 green buttons are removed from the box, the number of red buttons in the box will become 10 times the number of green buttons left in it. Find the number of red buttons in the box.

R=4G
R=10 x (G-45)

3.Tim and Lucy have 36 apples altogether. Tim will have 4 times as many apples as Lucy if Mun gives him another 29apples. How many apples does Tim have at the moment.

T+L=36
T+29 = 4L

4. There are a total of 158 candles in Carton Q and Carton U. If 47 candles are tr4ansferred from Carton U to Carton Q, the new respective new number of candles in the 2 cartons are equal. How many candles are there in Carton Q at the moment.

Q+U=158
U-47=Q+47


5. Hudson had twice as many marbles as Stuart. Hudson later gave 60 of his marbles to Presley; as a result, Stuart had three times as many marbles as Hudson. How many marbles did Hudson have at first.

H=2S
3 x (H-60)=S