QUESTION 1
200 primary school students were asked to choose either a hotdog or a pizza for lunch on their school trip.
52% of the students picked pizza.
56% of the students are girls.
\dfrac{1}{4} of the students who were girls chose hot dog.
How many boys chose pizza?
ANSWER:
20WRONG ANSWERS:
68
28
10
WORKING:
0.52 \times 200 = 104 students that chose pizza
0.56 \times 200 = 112 students were girls
\dfrac{1}{4} \times 112 = 28 girls chose hot dog
20 boys chose pizza.
QUESTION 2
500 people were asked what type of car they owned.
59\% of people owned a petrol car.
42\% of people asked were male.
72 people asked owned an electric/hybrid car.
\dfrac{2}{5} of people who owned a petrol car were female.
27 people were male and owned a diesel car.
How many females owned an electric/hybrid car?
ANSWER:
66WRONG ANSWERS:
6
106
86
WORKING:
0.59 \times 500 = 295 people asked owned a petrol car
0.42 \times 500 = 210 people asked where male
72 people asked owned an electric/hybrid car
\dfrac{2}{5} \times 295 = 118 of people who owned a petrol car were female
27 people were male and owned a diesel car
66 females owned an electric/hybrid car.
QUESTION 3
150 people were asked whether they prefer summer or winter.
There were twice as many people that preferred summer than winter.
32\% of people asked were children.
58\% of people that preferred winter were children.
How many adults preferred summer?
ANSWER:
81WRONG ANSWERS:
19
50
32
WORKING:
150 \times \dfrac{2}{3} = 100 of people asked preferred summer
0.32 \times 150 = 48 people asked were children
0.58 \times 50 = 29 people that preferred winter were children
81 adults preferred summer.