hailee1967 hailee1967

10-07-2018
Mathematics

contestada

It takes nora two hours to paint a wall 5m by 8m, and zack three hours to paint a wall 4m by 9m. together, how long will it take them to paint a wall 10m by 12m?

Respuesta :

mkryukova19 mkryukova19

10-07-2018

Nora's speed (5*8)m²/2h= 20 m²/h.
Zack's speed (4*9)m²/3h= 12 m²/h

Together for 1 h they paint (20+12) m²/h=32m²/h

Given area (10*12)m²=120 m²

120m² *1h/32m² = 3.75 h (3h 45 min) to paint 10m*12m together.

Answer Link

Otras preguntas

If (m, n) is the midpoint of the line seqment joining the center of the circle , (x - 3) ^ 2 + (y + 4) ^ 2 = 10 then |m| + |n|=

What is 3% written as a fraction? (in simplest form)

When chemists work with solid materials, we simply weigh out amounts of solid reagents and calculate mole amounts when thinking about stoichiometry. However, wh

Brown (B) is dominant to blue (b). BB X bb gives what percent offspring having brown eyes?

The Indians did not understand the European notion of "total war" because for them, war was not about destroying your opponent, as there was nothing in their wo

2 Points Which best describes the factors that affect a phenotype? O A. The genotype and the environment both affect phenotype. B. The phenotype is determined o

what is the sum of m and 3 divided by the difference of m minus 3

According to the provisions of the War Powers Resolution of 1973 as described in the passage, if the President perceives that an international conflict warrants

Matter with no definite volume and no definite shape is a ____.

The ___________ is how steep a straight line is. a y-intercept b y-axis c x-axis d slope