Can someone explain how you work the answer out to this on a calculator please

Q5 Loads of ways ...

Seperating left "wing" from the rest ...

area of Left wing = 15 * 22 = 330 cm2

area of rest of item = 18 * 30 = 540 cm2

total = 330 + 540 = 870 cm2


You could separate the bottom "wing" instead

(15 * 18) + (15 * 40) = 870 cm2

you may have noticed both terms have 15 so you could have simplified to ...

(18 + 40) * 15 = 870 cm2 [note the brackets are important on this one]

voila

OR ... if you want to do the calculation in one go

15 * 22 + 18 * 30 = 870cm2 [works on modern scientific calculators)

(15 * 22) + (18 * 30) = 870 cm2 [for some older calculators)

Q6.

Ratio of 7:2 so there are 9 parts altogether (7 + 2)

We know 9 parts = 828 cm from the question

So each ONE part is 828/9 = 92 cm

We want 7 parts and 2 parts

7 * 92 = 644 cm

2 * 92 = 184 cm

Quick check is to add them together, 644 + 184 = 828 cm which is what the whole thing was so check is ok.

If I had bothered to read the question (doh!) I would have realised we just want the bigger part.

gawd! i dont think i'd get a 'c' in my maths gcse if i had to do it again!!!

i hate maths- got an 'f' in 5th year, another 'f' in 6th form. then a 'c' at night school in 1995. the only thing i can remember is percentages!

Hope this helps:-

22 x 15 = 330
18 x 30 = 540

Therefore 330 + 540 = 870 Answer A


7 + 2 = 9
828 Divided By 9 = 9.2
9.2 x 7 = 644 Answer E

Long time since I did O'levels!!