WAEC - Mathematics (2010 - No. 3)
A car uses one litre of petrol for every 14km. If one of petrol cost N63.00, how far can the car go with N900.00 worth of petrol?
420km
405km
210km
200km
Vysvetlenie
1 litre = N63.00
xlitres = N900.00
x x N63 = N900 x 1 litre
x = \(\frac{900}{63} \times litre\)
x = \(\frac{100}{7}\) litres
Also, 1 litre = 14km
\(\frac{100}{7}\) = y
y x 1 litre = \(\frac{100litre}{7}\) x 14km
y = 20km
xlitres = N900.00
x x N63 = N900 x 1 litre
x = \(\frac{900}{63} \times litre\)
x = \(\frac{100}{7}\) litres
Also, 1 litre = 14km
\(\frac{100}{7}\) = y
y x 1 litre = \(\frac{100litre}{7}\) x 14km
y = 20km