Respuesta :
Answer:
The number of pennies is 91 is an example for the situation
Step-by-step explanation:
you are looking for a number divisible by 7 and gives reminder 1 when divided by 2, 3, 5 and 6
So let us search in the multiple of 7
Multiples of 7 are 7, 14, 21, 28, 35, 42, 49, 56, 63, 70, 77, 84 , 91, ...
∵ All even numbers divisible by 2
∴ The multiple of 7 must be odd
∵ The multiple of 7 gives remainder 1 with 2, 3, 5, 6
- Find the common multiple of 2, 3, 5, 6 and add 1 to it
∵ The common multiplies of 2, 3, 5, 6 are 30, 60, 90, 120, 150, ......
∵ 30 is the 1st common multiple of them
∵ 30 + 1 = 31
∵ 31 is not a multiple of 7
∴ 31 is not the answer
∵ 60 is the 2nd common multiple of them
∵ 60 + 1 = 61
∵ 61 is not a multiple of 7
∴ 61 is not the answer
∵ 90 is the 3rd common multiple of them
∵ 90 + 1 = 91
∵ 91 is a multiple of 7
∴ 91 is divisible by 7 and gives remainder 1 with 2, 3, 5, 6
∵ 91 ÷ 2 = 45 and remainder 1
∵ 91 ÷ 3 = 30 and remainder 1
∵ 91 ÷ 5 = 18 and remainder 1
∵ 91 ÷ 6 = 15 and remainder 1
∵ 91 ÷ 7 = 13 without remainder
∴ The number of pennies is 91
Using multiples and remainder of divisions, it is found that there were 91 coins.
------------------------------
- When they are put in groups of seven there are no pennies left over, thus, the number of coins is a group of 7.
- The remainder of the divisions of the number of coins n by 3, 5 and 6 is of 1.
------------------------------
Shortening the possibilities, we look at odd multiples of 7, which are: {7, 21, 35, 49, 63, 77, 91, 105, 119, ...}
- Odd and remainder of the division by 5 being 1 means that the last digit of the number is 1.
- The remainder of 21 divided by 6 is 3, so 21 is not the answer.
- For 91, the three remainders(division by 3, 5 and 6 are 1), thus, there were 91 coins.
A similar problem is given at https://brainly.com/question/15903472