Q&A - PSLE Math

[nicnac]

Tks..Ninac..Appreciate greatly

You're welcome

[questionable_i]

Can anyone help me with this question? Thank you

[Ender]

∠CAD + ∠ACD = 90°, From (180° - 90°)

∠ACB = ∠ACD + 22°
∠BAC = ∠CAD + ∠DAB

∠ACB + ∠BAC = 180° - 41° = 139°
(∠ACD + 22°) + (∠CAD + ∠DAB) = 139°
∠CAD + ∠ACD + 22° + ∠DAB = 139°
90° + 22° + ∠DAB = 139°
∠DAB = 139 - 90° - 22°
= 27° ##

[MathIzzzFun]

Can anyone help me with this question? Thank you

At point D, angle ADC (90°) + angle ADC (reflex) = 360°

In quadrilateral BCDA,
angle DCB + angle CBA + angle BAD + angle ADC (reflex) = 360°
∴ angle DCB + angle CBA + angle BAD =90°

angle BAD = 90° - 22° - 41° = 27°

cheers.

[Fly2high]

Hi , pls help on the below question .


Diana had 200 coins in her coin box. There were only 10-cents,20-cents and 50cents coins. First she
Replaced all her 20-cent coins with 50-cent coins of the same value
And there were 146 coins in the box. Then she replaced all her 10-cent coins with 50-cent coins
Of the same value and there were 66 coins left in the box. How many 50-cent coins were there
In the box at first ?


Thanks very much !
Fly2High

[BigDevil]

vvv
A: 1708482
Subject: Math
Level: P6
Tags: Money
Source:
^^^
For every 5 20c coins, Diana exchanged for 2 50c coins -> 3 fewer coins with each exchange
200 - 146 = 54
54 / 3 = 18 exchanges of 5 20c coins
18 x 5 = 90 (20c coins)

For every 5 10c coins, Diana exchanged for 1 50c coin -> 4 fewer coins with each exchange
146 - 66 = 80
80 / 4 = 20 exchanges of 5 10c coins
20 x 5 = 100 (10c coins)

Number of 50c coins -> 200 - 90 - 100 = 10

[Fly2high]

Thanks very much Big Devil !!

[BigDevil]

Welcome!
Glad to help.

[questionable_i]

Can anyone help me with this question?

[Ender]

Can anyone help me with this question?

Let number of tin at first be u

20 X u = 16 X (u+5)
20u = 16u + 80
4u = 80
u = 20 ###