While flinn was starting the fire, his friends were collecting firewood. flinn has 5 sticks. if he puts 3 sticks in the fire every minute, and his friends bring 7 sticks every minute, how many minutes will they need to make a pile of 45 sticks next to their fire?

Time required to make a pile of 45 sticks next to their fire = 10 minutes

Step-by-step explanation:

This is an example of arithmetic progression.

First term = 5 - 3 + 7 = 9 sticks

Common difference = 7 - 3 = 4 sticks.

So the number of sticks next to their fire is increasing like this

        9, 13, 17, 21 .............

term of AP = a + (n-1) d, we need to find n

  a + (n-1) d = 45

  9 + (n-1) x 4 = 45

  (n-1) x 4 = 36

   n - 1 = 9

    n = 10

Time required to make a pile of 45 sticks next to their fire = 10 minutes

marco saved more.   he saved $35 more.

step-by-step explanation:

1+2+3+4+5+6+7+8+9+10 = 55

2*10 = 20

55-20 = 35

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step-by-step explanation: