1) A chemistry teacher requires 250 milligrams of a chemical for an experiment. He has 30 grams of the chemical. How many times can he carry out the experiment?
2) A bottle contains 1.5 litres of cola. Hannah drinks 300 ml of the cola and Ben drinks 450 ml.How much of the cola is left?
3) Emma estimates that the mass of one sweet is 20 grams. A packet contains 0.36 kg of these sweets. How many sweets would you expect to find in the packet?
1. what is 30000/250 ?
2. what is 1500 - 300 - 450?
3. 1 kg = 1000 g
what do you think?
400
30000/250
=120 times
To answer these questions, we need to convert units and perform some basic calculations. Let's break it down step by step.
1) Chemical experiment:
a) We have 30 grams of the chemical, but we need to find out how many milligrams are in 30 grams.
b) There are 1000 milligrams in 1 gram, so we multiply 30 grams by 1000 to convert grams to milligrams.
30 grams * 1000 = 30000 milligrams.
c) The teacher requires 250 milligrams for each experiment, so we divide the total milligrams (30000) by the required milligrams (250) to find out how many times the experiment can be carried out.
30000 milligrams / 250 milligrams = 120 experiments.
Therefore, the chemistry teacher can carry out the experiment 120 times.
2) Cola remaining:
a) The bottle contains 1.5 litres of cola, but we need to subtract the amount that Hannah and Ben drank.
b) Hannah drank 300 ml and Ben drank 450 ml, so we add these two quantities to find the total amount they drank.
300 ml + 450 ml = 750 ml.
c) To find the amount of cola remaining, we subtract the total amount they drank from the initial amount in the bottle.
1500 ml - 750 ml = 750 ml.
Therefore, there will be 750 ml of cola left.
3) Number of sweets:
a) Emma estimates that the mass of one sweet is 20 grams, and we want to find out how many sweets are in a packet.
b) The packet contains 0.36 kg of sweets, but we need to convert it to grams since the mass of one sweet is given in grams.
0.36 kg * 1000 = 360 grams.
c) To find out how many sweets are in the packet, we divide the total mass of the packet by the mass of one sweet.
360 grams / 20 grams = 18 sweets.
Therefore, we would expect to find 18 sweets in the packet.