Question

Priya and meena , alone can complete a sketch in 15 days and 20
days respectively. If they do sketching together for 4 days ,
then what is the amount (in units) of sketch left if the total
sketch is for 225 units?

Answer 1

900 because  if we multiply 4 with 225 then the answer is 900 units

Answer 2

Answer:

120 units

Step-by-step explanation:

Priya can complete sketch in days = 15

Part of sketch can be done by Priya in 1 day = $\frac{1}{15}$

Meena can complete sketch in days = 20

Part of sketch can be done by Meena in 1 day = $\frac{1}{20}$

Part of sketch can be done in one day if they work together =  $\frac{1}{20}+\frac{1}{15}$

                                                                                                    =  $\frac{7}{60}$

If they work together for 4 days .

So, part of sketch done by them together in 4 days =  $\frac{7}{60} \times 4$

                                                                                      =  $\frac{28}{60}$

Since the sketch is of 225 units.

So,The amount of sketch is done by them together in 4 days = $\frac{28}{60} \times 225$

                                                                                                       =$105$

So, amount of sketch left = 225-105 = 120 units

Hence the amount of sketch left is 120 units.