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2 years ago

Jamar is four times as old as Josh. In 20 years he will be twice as old as Josh. How old is Jamar?

Mathematics

1 answer:

Juliette [100K]2 years ago

5 0

Simultaneous equations
Jamar=J
Josh=j
4J=j
20+J=2j
Then
4J=j
-4 (J)=-4(2j-20)
So
0=-7j+80
7j=80
j=80÷7

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Liam's breakfast was an egg and cheese biscuit with a carton of milk. He spent a total of $5.65. Finn spent $7.65 on an egg and

ruslelena [56]

Answer:

An egg and cheese biscuit was $3.65.

Step-by-step explanation:

Liam's breakfast was:

$P = E + C + M$

Where:

P: total price

E: egg

C: cheese biscuit

M: carton of milk

$P = E + C + M$

$5.65 = E + C + M$ (1)

Now, Finn's breakfast was:

$P = E + C + 2*M$

$7.65 = E + C + 2*M$ (2)

By subtracting equation (2) from (1) we have:

$7.65 - 5.65 = 2M - M$

$M = 2$

Hence, the price of a carton of milk is $2, so by entering this value into equation (1) we can find the price of an egg and cheese biscuit:

$5.65 = E + C + M$

$5.65 - 2 = E + C$

$E + C = 3.65$

Therefore, an egg and cheese biscuit was $3.65.

I hope it helps you!

7 0

2 years ago

Father can do the job on the farm in 6 hours. The older son can do it in 8 hours. The younger son can do same job in 12 hours. H

FrozenT [24]

Answer: it will take a combined rate of 2.67 hours

Step-by-step explanation:

Father can do the job on the farm in 6 hours. This means that the father's unit rate of working will be 1/6

The older son can do it in 8 hours. This means that the older son's rate of working will be 1/8

The younger son can do same job in 12 hours. This means that the younger son's working rate is 1/12

When they work together, they will be working simultaneously. It means that their unit rates are additive. The combined unit rates will be

1/6 + 1/8 + 1/12 = (20 + 15 + 10)/120

45/120

Assuming it takes t hours for them to complete the work while doing it together. Their combined unit rate will be 1/t

45/120 = 1/t

45t = 120

t = 120/45 = 2.67 hours

3 0

2 years ago

The gardener wanted to find the best water to use for growing his plants. If plants need a more neutral pH water for optimal gro

faltersainse [42]

Answer:

Answer:B

Step-by-step explanation:

3 0

2 years ago

Wilbur spends 2/3 of his income, share 1/12, and saves the rest. What part of his income does he save? Give the answer in simple

scoundrel [369]

Answer:

1/4 of his income.

Step-by-step explanation:

If Wilbur spends 2/3 of his income, 1/3 or 4/12 of it is left for other purposes (It is easier if everything has a common denominator of 12). And if he shares 1/12 of that remaining amount, there is 3/12 left. And when we simplify 3/12, we get 1/4.

*Mark me brainliest!*

7 0

2 years ago

Half of a set of the parts are manufactured by machine A and half by machine B. Ten percent of all the parts are defective. Six

baherus [9]

Answer:

The probability that a part was manufactured on machine A is 0.3

Step-by-step explanation:

Consider the provided information.

It is given that Half of a set of parts are manufactured by machine A and half by machine B.

P(A)=0.5

Let d represents the probability that part is defective.

Ten percent of all the parts are defective.

P(d) = 0.10

Six percent of the parts manufactured on machine A are defective.

P(d|A)=0.06

Now we need to find the probability that a part was manufactured on machine A, and given that the part is defective :

$P(A|d) =\frac{P(A \cap d)}{P(d)}$

$P(A|d) =\frac{P(d|A)\times P(A)}{P(d)}\\P(A|d)= \frac{0.06\times 0.5}{0.10}$

$P(A|d)= 0.3$

Hence, the probability that a part was manufactured on machine A is 0.3

8 0

2 years ago