Question

a does 20% less work than B if a can finish a piece of work in 7 and half hour and B can finish it in?? ​

Answer 1

Answer:

let work done by B be x

work done by A is x - 20% of x

time taken by A= 7.5 hrs

X - (20/100)x = 7.5 hrs

80/100x = 7.5 hrs

x =

7.5  \times 100 \div 80

9.375 hrs according to calculater

Answer 2

$\huge\underline\blue{\sf Answer:}$

$\large\red{\boxed{\sf Work\:finished\:by\:B=6hrs }}$

$\huge\underline\blue{\sf Solution:}$

$\large\underline\pink{\sf Given: }$

• "A" does 20% less work than "B" i.e 80%

• "B" do 100% work

• "A" finish its work in $\sf{7{\frac{1}{2}}}$ hrs

Here 100% And 80% is efficiency of A and B

$\large\underline\pink{\sf To\:Find: }$

• "B" can finish work in = ?

━━━━━━━━━━━━━━━━━━━━━━━━━━

A = 80%

$\large\implies{\sf {\frac{15}{2}}hrs}$

B = 100%

$\large\implies{\sf ? hrs}$

Work finished by B =$\large\sf{{\frac{80×15/2}{100}}}$

$\huge\red{♡}$$\large\red{\boxed{\sf Work\:finished\:by\:B=6hrs }}$