If 20 man or 30 boys can do a piece of work in 36 days, in how many days will 10 men and 12 boys do it? a. 15 C: 30 b. 20 d. 40. ​

d. 40

Step-by-step explanation:

20 men = 30 boys = 36 days

1 man = 36 ÷ 20

         = 2.8

1 boy = 36 ÷ 30

        = 1.2

10 men + 12 boys = (10×2.8) + (12×1.2)

                             = 28 + 14.4

                             = 42.4

                             ≈ 40

518,400

step-by-step explanation:

the area is multiplying all the given measurements together.

40 * 18 * 30 * 24 = 518,400

solution:

→c= a b , that is product of a and b is possible only when when a is m × n matrix and b is n × p matrix.

that is, number of columns of a= number of rows of b.

so, size of matrix , c= a b is , if a = (m × n)matrix

b= (n × p)matrix

then a b = [ (m × n)matrix] ×[   (n × p)matrix ]

→→c= a b= [m × p ] matrix

→→size of product a b will be equal to = number of rows of a × number of columns of b