Scientific Notation, Percentages & Simple Interest Quiz

1) A man is paid Dh16.75 an hour for a 42 hour week , his weekly wage is

Dh702.5

Dh705.3

Dh703.5

Dh703.05

The man is paid Dh16.75 per hour for a 42-hour week. To find his weekly wage, we multiply the hourly rate by the number of hours worked. Dh16.75 multiplied by 42 equals Dh703.5. Therefore, his weekly wage is Dh703.5.

Explanation

The man is paid Dh16.75 per hour for a 42-hour week. To find his weekly wage, we multiply the hourly rate by the number of hours worked. Dh16.75 multiplied by 42 equals Dh703.5. Therefore, his weekly wage is Dh703.5.

2) 0.0085 as scientific notation is

8.5 × 10 3

8.5 × 10 - 3

0.85 × 10 3

85 × 10 - 3

The given number, 0.0085, can be written in scientific notation as 8.5 × 10^-3. In scientific notation, the number is written in the form of a decimal number multiplied by a power of 10. In this case, the decimal number is 8.5 and it is multiplied by 10 raised to the power of -3, which means the decimal point is moved 3 places to the left. This is the correct answer because it represents the original number in a concise and standardized format.

Explanation

The given number, 0.0085, can be written in scientific notation as 8.5 × 10^-3. In scientific notation, the number is written in the form of a decimal number multiplied by a power of 10. In this case, the decimal number is 8.5 and it is multiplied by 10 raised to the power of -3, which means the decimal point is moved 3 places to the left. This is the correct answer because it represents the original number in a concise and standardized format.

3) A woman is paid a salary of Dh39133.5 per year , his weekly wage is ( one year = 52.178 weeks )

Dh570

Dh750

Dh507

Dh705

The woman's yearly salary is Dh39133.5, and there are 52.178 weeks in a year. To find her weekly wage, we divide her yearly salary by the number of weeks in a year: Dh39133.5 / 52.178 = Dh750. Therefore, her weekly wage is Dh750.

Explanation

The woman's yearly salary is Dh39133.5, and there are 52.178 weeks in a year. To find her weekly wage, we divide her yearly salary by the number of weeks in a year: Dh39133.5 / 52.178 = Dh750. Therefore, her weekly wage is Dh750.

4) For 12 tins of tuna at Dh3.95 , I paid

Dh74.4

Dh47

Dh47.4

Dh44.7

The correct answer is Dh47.4 because if each tin of tuna costs Dh3.95, then 12 tins would cost 12 x Dh3.95 = Dh47.4.

Explanation

The correct answer is Dh47.4 because if each tin of tuna costs Dh3.95, then 12 tins would cost 12 x Dh3.95 = Dh47.4.

5) The commission of 8% paid on sales of Dh3000 is

Dh24.0

Dh24

Dh2.40

Dh240

The commission of 8% paid on sales of Dh3000 is Dh240 because 8% of Dh3000 is equal to (8/100) * Dh3000 = Dh240.

Explanation

The commission of 8% paid on sales of Dh3000 is Dh240 because 8% of Dh3000 is equal to (8/100) * Dh3000 = Dh240.

6) Hamad was given a 25% discount , if the price of an item is Dh85 , he is paid

Dh36.75

Dh63.75

Dh63.5

Dh67.35

If Hamad was given a 25% discount on the price of the item, it means he paid only 75% of the original price. To find the amount he paid, we can multiply the original price (Dh85) by 75% (0.75). Dh85 * 0.75 = Dh63.75. Therefore, the correct answer is Dh63.75.

Explanation

If Hamad was given a 25% discount on the price of the item, it means he paid only 75% of the original price. To find the amount he paid, we can multiply the original price (Dh85) by 75% (0.75). Dh85 * 0.75 = Dh63.75. Therefore, the correct answer is Dh63.75.

7) The simple interest for Dh4900 at 8% pa for 4 years is : ( I=PRT )

Dh1685

Dh1568

Dh1658

Dh1586

The formula for calculating simple interest is I = PRT, where I is the interest, P is the principal amount, R is the rate of interest, and T is the time period. In this case, the principal amount is Dh4900, the rate of interest is 8% per annum, and the time period is 4 years. Plugging in these values into the formula, we get I = 4900 * 0.08 * 4 = Dh1568. Therefore, the correct answer is Dh1568.

Explanation

The formula for calculating simple interest is I = PRT, where I is the interest, P is the principal amount, R is the rate of interest, and T is the time period. In this case, the principal amount is Dh4900, the rate of interest is 8% per annum, and the time period is 4 years. Plugging in these values into the formula, we get I = 4900 * 0.08 * 4 = Dh1568. Therefore, the correct answer is Dh1568.

8) Ahmed receives Dh18.5 per hour for the first 7 hours , and time and – a – half for next hours , if Ahmed works 12 hours he receives :

Dh826.25

Dh268.25

Dh286.25

Dh628.25

Ahmed receives Dh18.5 per hour for the first 7 hours, which means he earns 7 * Dh18.5 = Dh129.5 for those hours.
For the remaining 5 hours, he receives time and a half, which means he earns Dh18.5 * 1.5 = Dh27.75 per hour.
So, for the next 5 hours, he earns 5 * Dh27.75 = Dh138.75.
Adding up the earnings for the first 7 hours and the next 5 hours, Ahmed receives a total of Dh129.5 + Dh138.75 = Dh268.25 if he works 12 hours.

Explanation

Ahmed receives Dh18.5 per hour for the first 7 hours, which means he earns 7 * Dh18.5 = Dh129.5 for those hours.
For the remaining 5 hours, he receives time and a half, which means he earns Dh18.5 * 1.5 = Dh27.75 per hour.
So, for the next 5 hours, he earns 5 * Dh27.75 = Dh138.75.
Adding up the earnings for the first 7 hours and the next 5 hours, Ahmed receives a total of Dh129.5 + Dh138.75 = Dh268.25 if he works 12 hours.

9) Ahmed is paid Dh25 for an item , he given a discount of 20% , the original price was

Dh31.25

Dh31.52

Dh30.25

Dh32.25

To find the original price, we need to calculate the price before the 20% discount. We can set up the equation: original price - (20% of original price) = Dh25. Let x be the original price. Therefore, x - (0.2x) = 25. Simplifying the equation, we get 0.8x = 25. Dividing both sides by 0.8, we find x = 31.25. Hence, the original price was Dh31.25.

Explanation

To find the original price, we need to calculate the price before the 20% discount. We can set up the equation: original price - (20% of original price) = Dh25. Let x be the original price. Therefore, x - (0.2x) = 25. Simplifying the equation, we get 0.8x = 25. Dividing both sides by 0.8, we find x = 31.25. Hence, the original price was Dh31.25.

10) The price of a chess set is Dh240 , Ali is paid Dh180 , the percentage of discount is

20%

15%

30%

25%

The correct answer is 25% because the price of the chess set is Dh240 and Ali is paid Dh180, which means he received a discount of Dh60. To find the percentage of discount, we divide the discount amount (Dh60) by the original price (Dh240) and multiply by 100. This gives us a discount of 25%.

Explanation

The correct answer is 25% because the price of the chess set is Dh240 and Ali is paid Dh180, which means he received a discount of Dh60. To find the percentage of discount, we divide the discount amount (Dh60) by the original price (Dh240) and multiply by 100. This gives us a discount of 25%.

11) An item its price : ' Was Dh120 , now Dh78 , the reduction as a percentage of the original price is

25%

45%

30%

35%

The reduction as a percentage of the original price is 35%. This can be calculated by finding the difference between the original price (Dh120) and the reduced price (Dh78), which is Dh42. Then, divide this difference by the original price and multiply by 100 to get the percentage. In this case, (42/120) * 100 = 35%.

Explanation

The reduction as a percentage of the original price is 35%. This can be calculated by finding the difference between the original price (Dh120) and the reduced price (Dh78), which is Dh42. Then, divide this difference by the original price and multiply by 100 to get the percentage. In this case, (42/120) * 100 = 35%.