Answer:
16 + 3n
Step-by-step explanation:
a = 19 ; common difference = 22 - 19 = 3
a(n) = a + (n -1 ) *d
= 19 + (n-1)*3
= 19 + 3n - 3
= 16 + 3n
Weight of an grapefruit=weight of an orange+8% weight of an orange
weight of an apple=weight of an orange -10% weight of an orange
a.<span>By what percentage is the grapefruit heavier than the apple?
We should find the connection between grapefruit and an apple. We know the connection between the weight of a grapefruit and an orange, we know the connection between an orange and an apple, so this means we know the connection between a grapefruit and an apple.
</span>
weight of an grapefruit=weight of an <span>orange+8% weight of an orange
</span>weight of an orange=weight of an apple<span> +10% weight of an apple
</span>
-> weight of an grapefruit=weight of an apple+10% weight of an apple + 8%(weight of an apple+10% weight of an apple)= weight of an apple + 18% weight of an apple + 2% weight of an apple= <span>weight of an apple + 20% weight of an apple
</span><span>b.By what percentage is the apple lighter than the grapefruit?
</span>weight of an grapefruit=weight of an apple + 20% weight of an apple<span>
</span>
-> The apple ts 20% lighter than the grapefruit.
The rate for the first is 1 job / 35 minutes and for the second is 1 job / 15 minutes. So combined we get
r = 1/35 + 1/15
3×5×7r = 3 + 7 = 10
r = 10/(105) jobs per minute
We're interested in 1/r
1/r = 105/10 = 10.5 minutes per job
Answer: 10.5 minutes