An easier way of doing this would be to subtract the initial attitude from the final attitude and divide by the rate of increase
= 30000 - 6000÷4000
= 24000÷4000
=6mins
We are given : Cost of a gallon of milk = $2.50.
Cost of a cup of yogurt = $1.20.
Total money Monica has = $20.
Number of cups of yogurt Monica can buy = x.
And inequality made is also correct
1.20x + 2.5 ≤ 20.
Now, we need to solve it for x.
Subtracting 2.5 from both sides, we get
1.20x + 2.5 -2.5 ≤ 20 - 2.5.
1.20x ≤ 17.5
Dividing both sides by 1.20, we get
1.20x/1.20 ≤ 17.5/1.20.
x ≤ 14.5833...
Because it's less than 15, so final answer is : 14 is greatest number of cups of yogurt Monica can buy.
So,
First, we find the prime factored form (P.F.F.) of 65 and 91.
P.F.F. of 65: 5 * 13
P.F.F. of 91: 7 * 13
Find the common numbers
13
13 = G.C.F.
Note: This method works for finding any G.C.F. (find common primes)