Adam has a total of 20 hens and buffaloes.
The number of hens' legs is 14 less than the buffaloes' legs.
How many (a) hens and (b) buffaloes does Adam have?
Number of buffaloes |
Number of buffaloes' legs |
Number of hens |
Number of hens' legs |
Number of less hens' legs than buffaloes' legs |
20
|
20 x 4 = 80 |
0 |
0 x 2 = 0 |
80 - 0 = 80 |
19 |
19 x 4 = 76 |
1 |
1 x 2 = 2 |
76 - 2 = 74 |
9 |
9 x 4 = 36 |
11 |
11 x 2 = 22 |
36 - 22 = 14 |
(a)
If Adam has 20 buffaloes,
the number of legs
= 20 x 4
= 80
If Adam has 19 buffaloes and 1 hen,
number of less hens' legs than buffaloes' legs
= 19 x 4 - 1 x 2
= 76 - 2
= 74
Decrease in the number of legs when 1 buffalo is replaced by a 1 hen
= 80 - 74
= 6
Total decrease in the number of legs
= 80 - 14
= 66
Number of hens
= 66 ÷ 6
= 11
(b)
Number of buffaloes
= 20 - 11
= 9
Answer(s): (a) 11; (b) 9