Will give brainliest to best answer. 1) washing powder comes in three different sized boxes, 1kg, 2.5kg and 5kg. finlay wants to buy exactly 14kg of washing powder. what is the smallest number of boxes finlay can buy? 2) samah has made 20kg of chilli. there are 100g of chilli in a portion. how many portions of chilli has samah made? 3) kane has to take five 5000g parcels from the post office to his van. kane can safely lift 15kg at once. how many trips will kane need to take to move all of the parcels?

Problem One
Remark
If she doesn't mind having I kg left over, the minimum number would be 3 five kg boxes. If on the other hand, she must have exactly 14 kg then the minimum number is 6.

She needs 2 five kg boxes and 4 one kg boxes. <<<< Answer

Problem Two
There is a method of solving this that is called dimensional analysis. It is what should be used here. I'll do it at the end of the problem. In the meantime, you have to do it a slightly longer way.

1 portion = 100 grams.
x portions = 1kg which is 1000 grams.
x portions = 1000 grams.

Set up a proportion to find the number of servings in 1 kg
1 portion/x = 100 grams/1000 grams Cross multiply
1 * 1000 = 100 * x                                 Divide by 100
1000/100 = x
x = 10 servings in 1 kg.

So each kg produces 10 portions
1 kg / 10 portions = 20 kg / x portions Cross multiply
x * 1 = 10 * 20
x = 200 portions   <<<<< Answer

Dimensional Analysis
[1batch]*[1 portion/100g][1000g/kg][20kg/batch] the units cancel
1000 * 20 / 100 only the portions are left over.
200 portions is the answer.

Problem Three
1 kg = 1000 grams
x kg = 5000 grams  Cross multiply

1*5000 = 1000 x
x = 5 kg

1 parcel weighs 5 kg
x = 15 kg

15 kg = 5 x
x = 15/5
x = 3 

So he can carry 3 parcels per trip.

Since there are 5 such parcels, he will have to make 2 trips. The second one will not be a full load.
First Trip = 3 parcels
Second Trip = 2 parcels. <<<<Answer

With a continuous thought process.