Question

Mary, Misa and Mandy have a combined height of 4.84 m. Mary is 9 cm/0.009m

shorter than Misa. Misa is 0.05 m taller than Mandy. How tall, in metres, is
Mandy?

Answer 1

Hello!

Let’s start by assigning variables to each of the girls’ heights.

Mary=x

Misa=y

Mandy=z

Now, we know that Misa is 0.05 m taller than Mandy. Therefore we can say y (Misa’s height)= z (Mandy’s height) +0.05

Y=z+0.05


We also know that Mary is 0.009m shorter than Misa. Therefore, she must be 0.041 m taller than Mandy. We know this because Misa is 0.05 m taller than Mandy, and Mary is 0.009 meters shorter than Misa (0.05-0.009)= 0.041 Based on our determined variables, we can write this as:

X=z+0.041

OR REWRITTEN TO SOLVE FOR Z

Z=x-0.041

Finally, we know that the heights of all three girls are equal to 4.84 meters:

X+y+z=4.84


Let’s solve! Plug the second equation, solved for z, into the first equation.

Y= (x-0.041) +0.05

Now, let’s plug that in for “y” and the second equation in for “z” in the final equation:

X+ ((x-0.041) +0.05)+ (x-0.041)= 4.84

Solve for X:

1.624

Plug that number in for “X” in the second equation to get Mandy’s height (z)

Z=x-0.041

Z= 1.624-0.041


Mandy’s height is 1.583 m

I know this is a little confusing, but I hope this helped! If you have any questions, feel free to comment and I can help clarify!

Answer 2

Mandy is 1.613 m tall

Explanation:

Let us consider

Mary is A, Misa is B and Mandy is C

According to question,

A + B + C = 4.84 m...... (i)

From qsn

9 cm/0.009 m

= 9 cm/ 0.9 cm

= 10 cm

= 0.1 m

Then, A is 0.1 m shorter than B

i.e. A= B - 0.1 m

Also, B is 0.05 m taller than C

i.e B = C + 0.05m

We have to find height of C ( Mandy)

From eqn (i)

C = 4.84 - B - A

or, C = 4.84 - (C + 0.05) - ( B - 0.1)

or, C = 4.84 - C - 0.05 - B + 0.1

or, 2C = 4.89 - B

or, 2C = 4.89 - ( C + 0.05)

or, 2C = 4.89 - C - 0.05

or, 3C = 4.84

or, C = 4.84/3

or, C = 1.613 m