Maths lesson notes

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Jennie's council has a target of 1/5 for households to recycle their waste.

In January, Jennie recycles 1/10 of her household waste.

In February, she recycled 15 kg of 120 kg of household waste.

Her result for March was 13% recycled out of 112 kg of household waste.

Has Jenny met her household target?

Which was her best month?

4 MARK QUESTIONS

*First we need to convert all figures into fractions.*

Jan- 10% 1/10

Feb- 12.5% 1/8

March- 13% 13/100

*Then make the common denominator*

10/100 + 12.5/100 + 13/100 = 35.5/100

(Because the common denominator of 10, 8 and 100 is 100 the fractions are the same as the percentages therefore we use the percentage figures instead. 8 x 72.5 = 100)

Jenny has not met the Council target.

March was her best month.

A bag contains only red, yellow and blue discs.

The probability of drawing a red disc is 1/2.

The probability of of drawing a yellow disc at random is x.

The probability of drawing a blue disc at random is 4x.

One disc is to be selected at random. What is the probability it will be a blue disc?

*The probability must always add up to one.*

1/2 + x + 4x = 1

5x = 1/2 (or 0.5) x = 1

Probability of a blue disc = 4 X 0.1 = 0.4

Last year Sasha was paid 15400 pounds after deductions from her gross salary.

She was paid 70% of her gross salary. This year Sasha's gross salary increased by 2%.

Work out the increase in Sasha's gross salary. Give your answer in pounds.

(Gross income including salary and wages, dividends, interest and rent before any deductions are allowed.)

15400 = 70% wages

15400 / 70 X 100 = 22000

22000 X 0.02 = 22440

15400 = 70%

/ 70%

220 = 1% OR

X100 100%

22000

1.02

22440

440

22000

10% = 2200

1% = 220

2% = 440

MATHS NOTES FROM LESSONS.

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