Ratio and Rate practice questions

Secondary 1 topics, the foundation the O-Level Mathematics 4052 syllabus builds on. Every question below has a full worked solution.

When a student gets a question wrong in Math Amigo, it does not show the answer straight away. It reads the working, identifies the step that went wrong, and asks a question that points at the correction. The worked solution is there once a genuine attempt has been made.

Practise ratio and rate free

What this topic covers

Worked examples

Example 1

If x:21=4:3x : 21 = 4 : 3, find the value of <i>x</i>.
Show the worked solution
  • $\frac{x}{21} = \frac{4}{3}$
  • $x = \frac{4 \times 21}{3}$
  • $= 28$

Answer: 2828

Example 2

A machine produces pages at a rate of 88 per hour. How many pages are produced in 55 hours?
Show the worked solution
  • $\text{Total} = \text{Rate} \times \text{Time}$
  • $= 8 \times 5$
  • $= 40$

Answer: 4040

Example 3

\4000isinvestedat is invested at 4\%perannumsimpleinterest.Howmanyyearswillittaketoearn per annum simple interest. How many years will it take to earn \800800 in interest?
Show the worked solution
  • $I = \frac{P \times R \times T}{100}$
  • $800 = \frac{4000 \times 4 \times T}{100}$
  • $T = \frac{800 \times 100}{4000 \times 4}$
  • $= 5 \text{ years}$

Answer: 55

Questions parents ask

Is it really free?

The free plan is permanent and does not ask for a card. It has daily limits on the AI feedback, and the paid plans lift them.

Which syllabus does this follow?

O-Level Mathematics (4052), for Singapore secondary students. Math Amigo covers Secondary 1 to 4, both O-Level Mathematics and Additional Mathematics.

Will it just show my child the answer?

No. On a wrong answer it looks at the working, points to the step that went wrong, and asks a question that helps the student find the correction. The full worked solution is available after a genuine attempt.

Other Secondary 1 topics