In a field there are cows, birds, and spiders. Spiders have 4 eyes and 8 legs each. In the field there are 20 eyes and 30 legs.
1 answer:
Answer:
1 spider, 3 cows, 5 birds.
Step-by-step explanation:
Cows (C): 4 legs, 2 eyes.
Birds (B): 2 legs, 2 eyes.
Spiders (S): 8 legs, 4 eyes.
The number of legs and eyes are given, respectively by:
Multiplying the second equation by -2 and adding it to the first one gives us the number of birds:
Rewriting the original equations with B =5:
Since the number of cows cannot be negative, and both C and S must be odd numbers, the only possible value of S is 1:
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We want to change the digit in the number 5,341 into 5,841, and to find the difference between the numbers.
Refer to the figure shown below.
The number 3 is in the 3rd place (hundreds) of the number 5,341 as a digit.
It is replaced by 8 to form the number 5,841.
This means that 300 is replaced by 800 because, in the third place, we count by hundreds in the 3rd place.
The difference between 800 and 300 is 500.
Subtraction of 5,341 from 5,841 also yields 500.
Answer:
The digit is in the 3rd place (hundreds).
The difference between the numbers is 500.
Refer to the figure shown below.
The number 3 is in the 3rd place (hundreds) of the number 5,341 as a digit.
It is replaced by 8 to form the number 5,841.
This means that 300 is replaced by 800 because, in the third place, we count by hundreds in the 3rd place.
The difference between 800 and 300 is 500.
Subtraction of 5,341 from 5,841 also yields 500.
Answer:
The digit is in the 3rd place (hundreds).
The difference between the numbers is 500.
