We know that area DXC = half of area of rectangle = 60. Since area DXY = 10, so area DYC = 60-10 = 50. An important concept to know is that area DZC = area DXC since they have the same base and height. Since area DYC is common, so area YZC = 10. Total shaded area = area rectangle - area DXC - area YZC = 120 - 60 - 10 = 50.

Thanks alot!

You made that very clear VeiLi, my working out would have taken many more steps.

My working

Qn got mistake. :)

90 divide by 2 then multiply by 5

Shld be "Peter had 90 stamps less than David" or "David had 90 stamps more than Peter"

Nooo

Question got prob

Didnt read carefully lol

PETER/ DAVID = 2/5

PETER/ DAVID = 2/5

PETER/ DAVID = 2/5 Here difference between them is 3

But it is given David has 90 more hence multiply each term by 30

PETER 2*30 = 60 AND DAVID 5*30 = 150 TOTAL WITH THEM IS 240

BUT THE QUESTION SHOULD BE DAVID HAS 90 MORE MARBLES

Thks

120+120=240 is equal to 3unit at B A left 1 unit B have 240 + 1unit 1 unit is 240÷3=80 So A have 1 unit + 120 away. A n B have 200 each at 1st. Total is 400

320

6 erasers and 18 rulers are $6; 15 rulers are $3; 1ruler is $0.20; 1 rubber is $0.40.

If we multiply the first line by 2, we will get double the erasers (12), rulers (6) and cost ($6). Then because the number of rulers (6) are equal as line 2, we can subtract the erasers and cost to know that 10 erasers costs $4 and one eraser is $0.40, etc.

Another way is to multiply the second line by 3 so that we get equal number of eraser as line 1. This way, we subtract the erasers to find the cost a certain number of rulers.

Thanks for all the help and for explanation! I need it.

This is a before and after question where the total number of units (or money) does not change. You can convert this to a model ....

Thanks.