The average of 5 and 9 is?
7
Tom and Jerry scored an average of 72 marks for their tests. If tom scored 4 fewer marks than Jerry, how many marks did Tom score?
Total - 72 x2 = 144
Jerry - (144-4) / 2
Tom - 70 +4 = 74 Marks
The average cost of 3 books is $2.10. Their total cost is?
$6.30
The average score of 4 boys for a maths test is 76 marks. Another boy, Daniel joins in and the average becomes 74 marks. What is Daniel's score?
Total - 74 x 5 = 370
76 x 4 = 304
370 - 304 = 66 marks
Mr. Chris Rocky weighed six chickens and worked out their average mass as 1.75kg. The mass of one of the chickens was 1.9 kg. Find the total mass of the other five chickens.
8.6kg
The average length of 3 ribbons is 1.2m. If the total length of two ribbons is 2 m 10 cm, what is the length of the remaining ribbon? Give your answer in centimeters.
1.2 x 3 = 3.6 m
3.6 -2.1 = 150cm
The total mass of Barrel A and Barrel B is 74kg. The total mass of barrel B and Barrel C is 97kg. The mass of Barrel C is twice the mass of Barrel A. What is the average mass of the three barrels?
A = 97 - 74
= 23kg
C = 97 + 74 / 3
= 57
57 + 23 = 80/2
=40kg
Luna wants to find out what her average grade is for midterms; here are her scores.
English 94, Science 88, Math 96, IT 58What is Luna’s average grade for midterms? What calculation do I need to make?
84%
The sum of 14 numbers is 119. If the sum of 2 of the numbers is 23, find the average of the remaining numbers.
114 - 23 / 12 = 8
200 type A and Type B boxes were weighed before shipment. The average mass of the boxes was 15kg. The average mass of type A boxes was 12kg. The average mass of type B boxes was 20kg. How many type B boxes were there?
200 x 15 = 3000
3000/2 = 1500
1500/12 = 125
200-125 = 75 B type
A group of 6 boys scored 44,36,34,38,51 and 49 marks
A group of 4 girls scored 54,49,57 and 36.
Find the average of each group and decide who performed better.
Boys: 42
Girls: 49
The average mass of 2 ducks and 3 ducklings is 1.92kg. The average mass of 3 ducks and 5 ducklings is 1.85kg. All ducks have the same mass and all duckling have the same mass. What is the total mass of 2 ducks and 1 duckling?
1.92 x 5 = 9.6
1.85 x 8 = 14.8
1D +2d = 14.8 - 9.6 = 5.2kg
3D + 6d = 5.2 x 3 = 15.6 kg
1d = 15.6 - 14.8 = 0.8kg
1D = 5.2 - 1.6 = 3.6kg
2D + 1d = 2 x 3.6 + 0.8 kg
8kg