Model 5  Split & Fraction of work Section-Wise Topic Notes With Detailed Explanation And Example Questions

Answer: (d)

Using Rule 2,

The part of field cultivated by A in 1 day

= $2/{5 × 6} = 1/15$

The part of field cultivated by B in 1 day

= $1/{3 × 10} = 1/30$

The part of field cultivated by A and B together

= $1/15 + 1/30 = 3/30 = 1/10$

$4/5$ part of field cultivated by A and B together in

= ${4/5}/{1/10}$ days = ${4 × 10}/5 = 8$ days

Answer: (d)

Since, P does $1/4$ th work in 10 days.

P will do 1 work in 10 × 4 = 40 days

Since, Q, does 40% part of work in 40 days

Q will do 100% work in

${40 × 100}/40$ = 100 days

Since, R, does $1/3$ rd work in 13 days.

R will do 1 work in 13 × 3 = 39 days

Answer: (b)

Using Rule 2,

A can do the whole work in ${20 × 5}/4 = 25$ days

Remaining work = $1 - 4/5 = 1/5$

(A + B)’s 1 day’s work = $1/15$

and A’s 1 day’s work = $1/25$

B’s 1 day’s work

= $1/15 - 1/25 = {5 - 3}/75 = 2/75$

B can finish the work in $75/2$ days

i.e., 37$1/2$ days

Answer: (c)

Using Rule 2,

A does $7/8$ work in 28 days.

A will complete the work in

$28 × 8/7$ = 32 days.

B does $5/6$ work in 20 days.

B will complete the work in

${20 × 6}/5$ = 24 days

(A + B)’s 1 day’s work

= $1/32 + 1/24 = {3 + 4}/96 = 7/96$

Required time = $96/7 =13{5}/7$ days

Answer: (c)

Using Rule 1,

Remaining work

= $1 - 5/8 = 3/8$ ;

Remaining time = 4 days

${M_1D_1}/W_1= {M_2D_2}/W_2$

${20 × 12}/{5/8} = {M_2 × 4}/{3/8}$

${20 × 12}/5 = {M_2 × 4}/3$

4 × 12 = ${M_2 × 4}/3$

$M_2$ = 12 × 3 = 36

Number of additional workers = 36 - 20 = 16

Answer: (d)

Using Rule1,

$7/8 : 1 8 : : 28 : x$

where x is no. of men

$7/8 × x = 1/8 × 28$

$x = {28 × 8}/{7 × 8}$ = 4