Sec 4 Quick Revision 1

Sima and Ken share $480 in the ratio 9:7.

Find the amount each receives.

• Sima receives $270 and Ken receives $210.

• Sima receives $250 and Ken receives $230.

• Sima receives $300 and Ken receives $180.

• Sima receives $300 and Ken receives $180.

Answer explanation

To find the amounts Sima and Ken receive, divide $480 in the ratio 9:7. This gives $270 to Sima and $210 to Ken, which matches the correct choice.

• 68.5, 111.5

• 45.7, 134.3

• 89.5, 90.5

• 59.3, 120.7

Answer explanation

The correct values of x can be found by taking the inverse sine of 0.9301, which gives approximately 68.5 and 111.5 degrees within the range of 0 to 180 degrees.

Convert 1.36 radians into degrees.

• 45.3

• 90.7

• 180.2

• 77.9

Answer explanation

To convert radians to degrees, multiply by 180/π. Therefore, 1.36 radians * (180/π) ≈ 77.9 degrees. The correct answer is 77.9.

Answer explanation

To simplify (2c^3d^2)^3, we raise each term inside the parentheses to the power of 3. This gives us 2^3 * c^(3*3) * d^(2*3) = 8c^9d^6.

• 3

• 6

• 8

• 4

Answer explanation

To solve the equation, simplify the left side: 16*5^4 + 9*25^2 = 16*625 + 9*625 = 10000 + 5625 = 15625. Therefore, 5^6 = 5^k, which implies k = 6, so the correct answer is 6.

Ravi invests $4500 at a rate of 0.25% per month compound interest.

Calculate the value of his investment at the end of 12 months.

• $4636.87

• 65483.62

• $4635

• $5625

Answer explanation

The correct answer is $4636.87. Using the compound interest formula A = P(1 + r/n)^(nt), where A is the final amount, P is the principal, r is the interest rate, n is the number of times interest is compounded per year, and t is the time in years, we can calculate the value of the investment at the end of 12 months.

• a = 7, b = 25

• a = -7, b = 24

• a = -7, b = 49

• a = -7, b = 25

Answer explanation

To find a and b, compare the given expression with the expanded form of (x+a)^2. By comparing coefficients, a = -7 and b = 24.

Adrian has 550 stamps in his collection.

He increases his number of stamps by 18%.

Find the number of stamps in his collection now.

• 649

• 605

• 712

• 498

Answer explanation

Adrian increased his 550 stamps by 18%, which is 99 stamps. Adding this to his initial collection gives a total of 649 stamps now.

May collects postcards.

28% of the postcards are from Australia.

55% of the remaining postcards are from Europe.

The other 81 postcards are from Asia.

Calculate the total number of postcards in her collection.

• Total number of postcards in May's collection is 400.

• Total number of postcards in May's collection is 300.

• Total number of postcards in May's collection is 250.

• Total number of postcards in May's collection is 350.

Answer explanation

The correct answer is the total number of postcards in May's collection is 250. This is calculated by finding 28% from Australia, 55% from Europe, and the remaining 17% from Asia, totaling 100%.

Allan travels from Singapore to France.

She wants to change 780 Singapore dollars ($) into Euros.

She would receive 1 Euro more if she changes the money in Singapore.

The exchange rate in France is 1 Euro = $1.5953.

Calculate the exchange rate in Singapore.

Give your answer in Euros per Singapore dollar.

• 0.626

• 0.627

• 0.628

• 0.629