SEAMO 2017 — Paper C — Grade 5–6 Question 19

Question 19

An escalator moves upwards at constant speed from floor one to floor three. Chiranjit walks at $2$ steps/s and arrives in $40$ s. Debdeep walks at $3$ steps per $2$ s and arrives in $50$ s. How many stationary steps span the escalator?

$100$
$90$
$80$
$70$
$60$