Make their height all the same as Tom's first.

4.89 m + 0.19 m + 29 cm

= 4.89 m + 0.19 m + 0.29 m

= 5.37 m

Now that's 3 times of Tom's height.

Tom's height = 5.37 m ÷ 3 = 1.79 m

Cliff's height = 1.79 m - 0.29 m
= 1.5 m

Thank you very much for your help

Welcome!

Alternative working :

Tom is 0.19 m taller than Bob since Bob is 0.19 m shorter than Tom.

29cm = 0.29 m
So Tom is 0.29 m taller than Cliff.

Comparing these two pieces of information,

0.29 m - 0.19 m = 0.1 m

We can deduce that Bob is 0.1 m taller than Cliff.

Now we make all the height the same as Cliff's.

4.89 m - 0.1 m - 0.29 m = 4.5 m

This is three times of Cliff's height.

Cliff's height = 4.5 m ÷ 3 = 1.5 m

Thank you very much for your explanation.

I got 1 more question cannot solve, may I know can you help?

A & B used 7.3 litres of while colour paint and 6/7 litres of pink colour paint to paint the house.
How many litres of paint did they use altogether?

No problem

Sorry I cannot take photo, because allow ask 1 question only

White paint : 7.3 litres

7.3 litres = 7 3/10 litres

Pink paint : 6/7 litre


The idea here is to make the denominator of the fraction the same so they can be added together.


White paint :
7 3/10 litres = 7 21/70 litres

(multiply both the numerator and denominator of the fraction part by 7)

Pink paint :
6/7 litres = 60/70 litre

(multiply both the numerator and denominator of the fraction part by 10)


Total paint used

= 7 21/70 litres + 60/70 litre ①

= 7 81/70 litres ②

= 7 litres + 70/70 litre + 11/70 litre ③

= 7 litres + 1 litre + 11/70 litre ④

= 8 litres + 11/70 litres ⑤

= 8 11/70 litres ⑥

You can skip directly from step ② to step ⑥ for this part. ③,④,⑤ are just there to show you how it's derived.


If you want to present as a decimal (to 2 decimal places),

11/70 ≈ 0.157142857

Then 8 11/70 litres

≈ 8.157142857 litres
= 8.16 litres (2.dp)

Kindly explain more about 7.3 litres how to change to 73l10?

7.3 litres

= 7 litres + 0.3 litres

Now 0.1 = 1 ÷ 10 = 1/10

So 0.3 = 0.1 x 3 = 3 x (1 ÷ 10) = 3 x 1/10
= 3/10

So,

7.3 litres

= 7 litres + 0.3 litres

= 7 litres + 3/10 litres

= 7 3/10 litres

Understand now. Thank you very much for teaching me. Good nite