55 pupils from Class V and Class W took a Mathematics test. The average marks of the pupils was 74 marks. The average marks of the pupils in Class V was 76 marks and the average marks of the pupils in Class W was 71 marks. How many pupils were there in Class V?
Pupils in
Class V |
Total scores in
Class V |
Pupils in
Class W |
Total scores in
Class W |
Total scores of
Class V and Class W |
55
|
55 x 76 =
4180 |
0
|
0
|
4180
|
54
|
54 x 76 =
4104 |
1
|
1 x 71 =
71 |
4175
|
33
|
33 x 76 =
2508 |
22
|
22 x 71 =
1562 |
4070
|
Total scores of Class W and Class V
= 55 x 74
= 4070
If all the pupils are in Class V,
total scores
= 55 x 76
= 4180
Big difference
= 4180 - 4070
= 110
Small difference
= 76 - 71
= 5
Number of pupils in Class W
= 110 ÷ 5
= 22
Number of pupils in Class V
= 55 - 22
= 33
Answer(s): 33
