T-Leng Tuition · mugcornersg.com
Total: 30 marksSuggested time: 50 minutes
Name: ______________________________Class: ____________ Date: ____________
Answer all questions. Show all your working. Give non-exact answers correct to 3 significant figures, or 1 decimal place for angles in degrees, unless the question says otherwise.
Section A
1(a)Find 20% of 120. Answer (a)[1]
(b)Find 5% of 120. Answer (b)[1]
2(a)The pass rate of a school's Mathematics examination fell from 80% to 65%. Find the decrease, in percentage points.
Answer (a)[1]
(b)The percentage of pupils in a school who cycle to school rose from 8% to 12%. Find the increase, in percentage points.
Answer (b)[1]
3Increase 500 by 15%. Answer[2]
4(a)A bicycle has a marked price of $240. It is sold at a discount of 10%. Find the selling price.
Answer (a)$[2]
(b)A watch has a marked price of $120. It is sold at a discount of 30%. Find the selling price.
Answer (b)$[2]
5(a)After losing 25% of its value, a car is worth $30,000. Find its value before the loss.
Answer (a)$[2]
(b)The number of visitors to a park fell by 20% to 400. Find the number of visitors before the fall.
Answer (b)[2]
Section B
6(a)A puppy had a mass of 3.5 kg. Its mass increased by 20% over a month. Find its new mass.
Answer (a)[2]
(b)An HDB block has 160 flats. 20% of the flats are four-room flats. Find the number of four-room flats.
Answer (b)[2]
(c)(i)A rice cooker has a marked price of $45. It is sold at a discount of 40%. Find the selling price.
Answer (c)(i)$[2]
(c)(ii)A printer has a marked price of $45. It is sold at a discount of 5%. Find the selling price.
Answer (c)(ii)$[2]
7(a)A rice cooker has a marked price of $45. It is sold at a discount of 40%. Find the selling price.
Answer (a)$[2]
(b)A car worth $50,000 loses 15% of its value in the first year and 10% of its value in the second year. Find its value after two years.
Answer (b)$[2]
(c)(i)A number increases from 40 to 60. Find the percentage increase. Answer (c)(i)%[2]
(c)(ii)The mass of a parcel was 2.5 kg. After repacking, its mass is 2.25 kg. Find the percentage decrease in its mass.
Answer (c)(ii)%[2]
END OF PAPER
Question 1
20% of 120=10020×120=24 5% of 120=1005×120=6 Question 2
(a)Answer: It decreased by 15 percentage points.[1] A change in percentage points is the difference between the two percentages.80−65=15It decreased by 15 percentage points. (b)Answer: It increased by 4 percentage points.[1] A change in percentage points is the difference between the two percentages.12−8=4It increased by 4 percentage points. Question 3
100%+15%=115%New value=100115×500=575 Question 4
(a)Answer: The selling price is $216.[2]
100%−10%=90%Selling price=10090×240=216The selling price is $216. (b)Answer: The selling price is $84.[2]
100%−30%=70%Selling price=10070×120=84The selling price is $84. Question 5
(a)Answer: Its value before was $40000.[2]
100%−25%=75%75%→300001%→7530000=400100%→400×100=40000Its value before was $40000. (b)Answer: There were 500 visitors before.[2] 100%−20%=80%80%→4001%→80400=5100%→5×100=500There were 500 visitors before. Question 6
(a)Answer: Its new mass is 4.2 kg.[2] 100%+20%=120%New value=100120×3.5=4.2Its new mass is 4.2 kg. (b)Answer: There are 32 four-room flats.[2] 20% of 160=10020×160=32There are 32 four-room flats. (c)(i)Answer: The selling price is $27.[2]
100%−40%=60%Selling price=10060×45=27The selling price is $27. (c)(ii)Answer: The selling price is $42.75.[2]
100%−5%=95%Selling price=10095×45=42.75The selling price is $42.75. Question 7
(a)Answer: The selling price is $27.[2]
100%−40%=60%Selling price=10060×45=27The selling price is $27. (b)Answer: Its value after two years is $38250.[2]
1st change: 100%−15%=85%2nd change: 100%−10%=90%Final value=50000×10085×10090=38250Its value after two years is $38250. (c)(i)Answer: =50%[2] Increase=60−40Increase=20Percentage increase=4020×100%=50% (c)(ii)Answer: =10%[2] Decrease=2.5−2.25Decrease=0.25Percentage decrease=2.50.25×100%=10%