model 9 average on cricket/exam Practice Questions Answers Test with Solutions & More Shortcuts

Answer: (d)

If the average in 10 tests be x, then,

x × 10 + 100 = (x + 5) × 11

⇒ 11x – 10x = 100 – 55

⇒ x = 45

∴ Required average = 50

Answer: (c)

Let the batsman make x runs. Total runs in 10 innings = 10 × 32 = 320

∴ ${320+x}/11$ = 32+4

⇒ 320 + x = 36 × 11

⇒ x = 396 – 320 = 76

Aliter : Using Rule 18,

If in the group of N persons, a new person comes at the place of a person of 'T’ years, so that average age,

increases by 't’ years

Then, the age of the new person = T + N.t.

Here, T = 32, N = 11, t = 4

Required Run = T + Nt

[Here N is taken as (n + 1)]

= 32 + 11 × 4

= 32 + 44 = 76

Answer: (d)

Let the number of wickets taken by the cricketer before the last match = x

According to the question,

${12.4x+26}/{x+5}$ =12.2

⇒ 12.4x + 26 = 12.2x + 61

⇒ 0.2x = 61 – 26 = 35

⇒ x = $35/{0.2}$=$350/2$=175

Answer: (b)

Runs scored in the next innings = x (let)

According to the question,

10 × 32 + x = 11 × 38

⇒ 320 + x = 418

⇒ x = 418 – 320 = 98

Aliter : Using Rule 18,

If in the group of N persons, a new person comes at the place of a person of 'T’ years, so that average age,

increases by 't’ years

Then, the age of the new person = T + N.t.

Here, T = 32, N= (10 + 1) = 11, t = 6

Required Runs = T + Nt

= 32 + 11 × 6

= 32 + 66 = 98

Answer: (a)

Let the number of runs scored in 11th innings be x.

∴ 10 × 50 + x = 11 × 52

⇒ 500 + x = 572

⇒ x = 572 – 500 = 72 runs

Aliter : Using Rule 18,

If in the group of N persons, a new person comes at the place of a person of 'T’ years, so that average age,

increases by 't’ years

Then, the age of the new person = T + N.t.

Here, T = 50, N = (10 + 1) = 11, t = 2

Required Runs = T + Nt

= 50 + 11 × 2 = 72