Q&A - PSLE Math
-
Hi,
Can tell me how to solve these questions?
(1). 4 jugs and 9 cups of water are used to fill 3/10 of a tank. Another 14 jugs of water are needed to fill the remaining part of the tank. How many cups of water can the tank hold?
(2). On a farm, Farmer Brown reared chickens, ducks and geese. 3/5 of the animals were chickens. Of the remainder, 3/4 were ducks and the rest were geese. The number of ducks was 18 more than the number of geese. In a flood, when some of the chickens drowned, the percentage of chickens became 55% of the animals.
(a). How many chickens were there on the farm at first?
(b). How many chickens drowned?
Thanks! -
Winx5015:
HiHi,
Can tell me how to solve these questions?
(1). 4 jugs and 9 cups of water are used to fill 3/10 of a tank. Another 14 jugs of water are needed to fill the remaining part of the tank. How many cups of water can the tank hold?
(2). On a farm, Farmer Brown reared chickens, ducks and geese. 3/5 of the animals were chickens. Of the remainder, 3/4 were ducks and the rest were geese. The number of ducks was 18 more than the number of geese. In a flood, when some of the chickens drowned, the percentage of chickens became 55% of the animals.
(a). How many chickens were there on the farm at first?
(b). How many chickens drowned?
Thanks!
Q1.
14 jugs --> 7/10 of tank
2 jugs --> 1/10 of tank
4 jugs --> 2/10 of tank
9 cups --> 3/10-2/10 = 1/10 of tank
9 x 10 = 90 --> The tank can hold 90 cups of water.
Q2.
Chickens : Ducks + Geese --> 6 : 4
Ducks : Geese --> 3 : 1
So, chickens : Ducks : Geese --> 6u : 3u : 1u
18 more ducks than geese, so 2u --> 18, 1u --> 9
Number of chickens : ducks : geese = 54 : 27 : 9
There were 54 chickens at first.
After some chickens drowned, percentage of chickens --> 55%
so, ducks + geese --> 45%
45% --> 27+9 = 36
5% --> 4
55% --> 44
There were 44 chickens left.
54-44 =10 chickens drowned.
cheers. -
Hi all, I’d appreciate yr help for the foll Qn:
Separate the following 8 numbers 26, 34, 57, 65, 69, 95, 119, 161 into 2 groups, each with 4 numbers so that the product of the 4 numbers in each group is equal.
thanks! -
YumYum:
HiHi all, I'd appreciate yr help for the foll Qn:
Separate the following 8 numbers 26, 34, 57, 65, 69, 95, 119, 161 into 2 groups, each with 4 numbers so that the product of the 4 numbers in each group is equal.
thanks!
26 = 2 x 13
34 = 2 x 17
57 = 3 x 19
65 = 5 x 13
69 = 3 x 23
95 = 5 x 19
119 = 7 x 17
161 = 7 x 23
Group 1 --> 26 (2 x 13) , 69 (3 x 23), 95 (5 x19), 119 (7x17)
Group 2 --> 34 (2 x 17) , 57 (3 x 19), 65 (5x 13), 161 (7 x 23)
cheers. -
Hi MathIzzzFun,
Thanks for your help!
Good Nite
-
Would somebody please check this (extract from My Pals are Here, Maths Homework - P6)
Question
-----------
The ratio of Jame’s age to Andy’s age is 2:7. In 8 years time, the ratio will become 2:5. Find Jame’s present age.
Answer
---------
Eqn 1: J/A = 2/7 -> 7J=2A
Eqn 2: (J+8) / (A+8) = 2/5 -> 5J + 40 = 2A + 16
Substitute eqn 1 into eqn 2
5J + 40 = 7J +16
7J-5J = 40-16
2J = 24
J = 12
James present age is 12 years old.
James : Andy
2 : 7
12 : 42
Andy is 42 years old.
After 8 years
James : Andy
2 : 5
20 : 50 (or 12+8 : 42+8) -
Is there a simpler method to solve this question (extract from My Pals are Here, Maths Homework, Primary 6A)
Question
-----------
Keith and Shawn each have some money. If Keith spends $38, the ratio of the amount of money Keith has to the amount of money Shawn has will become 2:5. If Shawn spends $38, the ratio will become 8:13. How much money does each boy have?
Answer
--------
Eqn 1: (K-38)/S = 2/5 -> 2S = 5K-190
Eqn 2: K/(S-38) = 8/13 -> 13K = 8S-304
Substitute eqn 1 into eqn 2 to get
13K = 4 (5K-190) - 304
K = 152
Solve eqn 1 using K=152
S = ((5x152) -190)/2 = 285
Keith has $152 and Shawn has $285 -
MathAche:
HiWould somebody please check this (extract from My Pals are Here, Maths Homework - P6)
Question
-----------
The ratio of Jame's age to Andy's age is 2:7. In 8 years time, the ratio will become 2:5. Find Jame's present age.
Answer
---------
Eqn 1: J/A = 2/7 -> 7J=2A
Eqn 2: (J+8) / (A+8) = 2/5 -> 5J + 40 = 2A + 16
Substitute eqn 1 into eqn 2
5J + 40 = 7J +16
7J-5J = 40-16
2J = 24
J = 12
James present age is 12 years old.
James : Andy
2 : 7
12 : 42
Andy is 42 years old.
After 8 years
James : Andy
2 : 5
20 : 50 (or 12+8 : 42+8)
Age difference will remain the same.
Present-
James : Andy --> 2 : 7 --> 6u : 21u
8 years' time-
James : Andy --> 2 : 5 --> 10u : 25u
So, 4u --> 8, 1u--> 2
Present age :
James --> 6u = 12 years old
Andy --> 21u --> 42 years old.
cheers. -
MathAche:
HiIs there a simpler method to solve this question (extract from My Pals are Here, Maths Homework, Primary 6A)
Question
-----------
Keith and Shawn each have some money. If Keith spends $38, the ratio of the amount of money Keith has to the amount of money Shawn has will become 2:5. If Shawn spends $38, the ratio will become 8:13. How much money does each boy have?
Answer
--------
Eqn 1: (K-38)/S = 2/5 -> 2S = 5K-190
Eqn 2: K/(S-38) = 8/13 -> 13K = 8S-304
Substitute eqn 1 into eqn 2 to get
13K = 4 (5K-190) - 304
K = 152
Solve eqn 1 using K=152
S = ((5x152) -190)/2 = 285
Keith has $152 and Shawn has $285
Total amount Keith and Shawn had left in both cases are the same.
Keith spends $ 38:
Keith : Shawn --> 2:5 --> 6u : 15u (total 21u)
Shawn spends $38:
Keith : shawn --> 8u : 13u (total 21u)
so 2u --> $38, 1u--> $19
Keith's money --> 8u --> 8 x $ 19 = $ 152
Shawn's money --> 15u --> 15 x $ 19 = $ 285
cheers. -
MathIzzzFun:
HiMathAche:
Would somebody please check this (extract from My Pals are Here, Maths Homework - P6)
Question
-----------
The ratio of Jame's age to Andy's age is 2:7. In 8 years time, the ratio will become 2:5. Find Jame's present age.
Answer
---------
Eqn 1: J/A = 2/7 -> 7J=2A
Eqn 2: (J+8) / (A+8) = 2/5 -> 5J + 40 = 2A + 16
Substitute eqn 1 into eqn 2
5J + 40 = 7J +16
7J-5J = 40-16
2J = 24
J = 12
James present age is 12 years old.
James : Andy
2 : 7
12 : 42
Andy is 42 years old.
After 8 years
James : Andy
2 : 5
20 : 50 (or 12+8 : 42+8)
Age difference will remain the same.
Present-
James : Andy --> 2 : 7 --> 6u : 21u
8 years' time-
James : Andy --> 2 : 5 --> 10u : 15u
So, 4u --> 8, 1u--> 2
Present age :
James --> 6u = 12 years old
Andy --> 21u --> 42 years old.
cheers.
MathIzzzFun.
typo error in your solution,
It should be 25u instead of 15u
cheers.
Hello! It looks like you're interested in this conversation, but you don't have an account yet.
Getting fed up of having to scroll through the same posts each visit? When you register for an account, you'll always come back to exactly where you were before, and choose to be notified of new replies (either via email, or push notification). You'll also be able to save bookmarks and upvote posts to show your appreciation to other community members.
With your input, this post could be even better 💗
Register Login