The equation in terms of "t"
1/t = ¹/₂₁ + ¹/₁₅
On solving the equation "t"= 8 ³/₄ days
Step-by-step explanation:
Time taken by roofer to shingle a roof- 15 hours
Time taken by apprentice-21 hours
Time required to shingle if both worked together- “t” hours
If roofer shingles the roof in 15 hours
Part of the roof he would shingle in 1 hours= ¹/₁₅
Similarly, part of the roof shingled by apprentice in 1 hour- ¹/₂₁
Part of the roof shingles when they worked together for 1 hours- 1/t = ¹/₂₁ + ¹/₁₅
Total time taken= 1/t = ¹/₂₁ + ¹/₁₅
1/t= ⁽²¹⁺¹⁵⁾ /₃₁₅
t= 315/36 = 8 ³/₄ days
