The ages of JingJing and her cousin are in the ratio of 4 : 7. In 5 years time, their ages will be in the ratio of 3: 5 How old is JingJing in 5 years time?

45 years old

Step-by-step explanation:

In this question, we have the present ratios of two cousins. Given their ratios is the next five years, we are asked to calculate what the age of Jingjin who is one of the cousins would be in the next five years.

Now, let’s look at their present ratio;

4:7

or we can just say let Jinngjin’s age be j and his cousin’s c presently

4:7 = j:c

4/7 = j/c

4c = 7j •••••••(i)

now in the next five, their ratio will be 3 to 5

mathematically, that is expressed as;

j+5:c+5 = 3:5

(j+5)/(c+5) = 3/5

5(j+5) = 3(c+5)

5j + 25 = 3c + 15

3c - 5j = 10. •••••(ii)

From 2 we can say c = (10+5j)/3

let’s put this into 1, we have;

4[(10+5j)/3] = 7j

40 + 20j = 21j

j = 40

In the next 5 years , j will be 40 + 5 = 45 years old

c.   x=2.4cm

step-by-step explanation:

similar triangles are triangles which have the same shape but not the same size. this means their angle measures are equal but their side lengths are not instead they are proportional. to solve, we will set up a proportion and solve.

a proportion is two equal ratios set equal to each other. we form the ratios by finding corresponding sides (sides which match to each other on both triangles by their position). out ratios will be one side of the small triangle over the corresponding side on the big triangle as shown below:

.

to solve the proportion, we'll cross multiply by multiplying numerator with denominator across the equal sign.

what is the answer?