Question

The height of two plants is in the ratio 7 : 9. The height if the taller plant is 26cm more than the height of the shorter plant. [3]

a) What is the height of taller plant?
b) What is the height of shorter plant?
c) What is their total length?

Answer 1

see explanation

Explanation:

Plants in ratio 7 : 9 = 7x : 9x ( where x is a multiplier )

Taller plant is 26 cm more than height of smaller, then

(a)

9x = 7x + 26 ( subtract 7x from both sides )

2x = 26 ( divide both sides by 2 )

x = 13

taller plant = 9x = 9 × 13 = 117 cm

(b)

shorter plant = 7x = 7 × 13 = 91 cm

(c)

total length = 117 + 91 = 208 cm

Answer 2

a) 117 cm b) 91 cm c) 208 cm

Explanation:

given smaller plant:taller plant = 7 : 9

let the height of smaller plant be x

then the height of taller plant will be x + 26

using this a equation can be formed:

9x = 7 ( x + 26 )

9x = 7x + 182

2x = 182

x = 91 cm ......this is the height of smaller plant

the height of taller plant will be:

x + 26 = 91 + 26 = 117 cm .............this is the height of taller plant

Now total length: 117 + 91 = 208 cm .....this is the total length.